U.S. patent application number 09/730925 was filed with the patent office on 2001-11-08 for adapter apparatus for interfacing an insertable and removable digital memory device to a host port.
Invention is credited to Jigour, Robin J., Wong, David K..
Application Number | 20010038547 09/730925 |
Document ID | / |
Family ID | 27104465 |
Filed Date | 2001-11-08 |
United States Patent
Application |
20010038547 |
Kind Code |
A1 |
Jigour, Robin J. ; et
al. |
November 8, 2001 |
Adapter apparatus for interfacing an insertable and removable
digital memory device to a host port
Abstract
Each device of a family of removable digital media devices may
be plugged into a host to permits the host to store data in it or
to retrieve data from it. The form factors of the digital media
devices and the connector system used by them are compact for
minimizing the volume of space occupied in portable devices and for
easy storage. Preferably, the digital media devices of the family
use serial memory requiring few power and signal lines, so that few
electrical contacts are required. For example, a small number of
durable contact pads form the contact arrays on the digital media
devices, which in conjunction with corresponding contact pads
mounted into a suitable socket provide for easy and convenient
insertion and removal and for robust and reliable electrical
contact over a long insertion lifetime. The digital media devices
interface to the host either directly or through adapters.
Inventors: |
Jigour, Robin J.; (San Jose,
CA) ; Wong, David K.; (San Jose, CA) |
Correspondence
Address: |
DAVID H. CARROLL
PO BOX 9004
AVON
CO
81620
US
|
Family ID: |
27104465 |
Appl. No.: |
09/730925 |
Filed: |
December 6, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09730925 |
Dec 6, 2000 |
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09435495 |
Nov 6, 1999 |
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6175517 |
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09435495 |
Nov 6, 1999 |
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09084044 |
May 22, 1998 |
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6026007 |
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09084044 |
May 22, 1998 |
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08823937 |
Mar 25, 1997 |
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5815426 |
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08823937 |
Mar 25, 1997 |
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08689687 |
Aug 13, 1996 |
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5877975 |
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Current U.S.
Class: |
365/43 ; 365/44;
365/63; 365/64 |
Current CPC
Class: |
Y02D 10/151 20180101;
Y02D 10/00 20180101; G06K 19/07741 20130101; G06K 19/07743
20130101; G06K 7/0021 20130101; G11C 2216/30 20130101; Y02D 10/14
20180101; G06K 19/07732 20130101; G06F 13/409 20130101; G11C 5/066
20130101 |
Class at
Publication: |
365/43 ; 365/63;
365/64; 365/44 |
International
Class: |
G11C 005/06; G11C
019/08 |
Claims
What is clamed is:
1. An adapter to interface a digital media device to a port of a
host, comprising: a host port connector; a socket for receiving a
digital media device; and a circuit mapping the host port connector
to the socket.
2. An adapter as in claim 1 wherein: the host port connector
comprises a serial data conductor, a power conductor, a ground
conductor, and a clock conductor; and the serial data conductor,
the power conductor, the ground conductor, and the clock conductor
are mapped to respective contact pads in the socket.
3. An adapter as in claim 2 wherein the socket conforms to an SPI
protocol.
4. An adapter for interfacing a memory device to a port of a host,
comprising: a host port connector; a socket having a plurality of
surface pad contacts and an orifice for receiving a generally
planar memory device having a plurality of surface pads; and a
circuit mapping the host port connector to the surface pad contacts
of the socket.
5. An adapter as in claim 4 wherein: the host port connector
comprises a serial data conductor, a power conductor, a ground
conductor, and a clock conductor; and the serial data conductor,
the power conductor, the ground conductor, and the clock conductor
are mapped to respective contact pads in the socket.
6. An adapter as in claim 5 wherein the socket conforms to an SPI
protocol.
7. An adapter for interfacing a memory device to a port of a host,
comprising: a host port connector comprising a serial data contact,
a clock contact, and a ground contact; a socket having a plurality
of surface pad contacts and an orifice for receiving a generally
planar memory device having a plurality of surface pads; and a
circuit mapping the data contact, the clock contact, and the ground
contact of the host port connector to respective ones of the
surface pad contacts of the socket.
8. An adapter as in claim 7 wherein the surface pad contacts of the
socket conform to an SPI interface protocol.
9. An adapter as in claim 7 wherein the surface pad contacts of the
socket conform to an NXS interface protocol.
10. An adapter for interfacing a memory device to a port of a host,
comprising: a host port connector comprising a serial data contact,
a clock contact, and a ground contact; a socket having a plurality
of contacts and an orifice for receiving a generally planar memory
device about 15 mm wide; and a circuit mapping the data contact,
the clock contact, and the ground contact of the host port
connector to respective ones of the contacts of the socket.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of copending U.S. patent
application Ser. No. 09/435,495, filed Nov. 6, 1999 (Jigour and
Wong, "Insertable and Removable Digital Memory Apparatus"); which
is a divisional of U.S. patent application Ser. No. 09/084,044,
filed May 22, 1998, now U.S. Pat. No. 6,026,007, issued Feb. 15,
2000 (Jigour and Wong, "Insertable and Removable High Capacity
Digital Memory Apparatus and Methods of Operation Thereof"); which
is a continuation of U.S. patent application Ser. No. 08/823,937,
filed Mar. 25, 1997, now U.S. Pat. No. 5,815,426, issued Sep. 29,
1998 (Jigour and Wong, "Adapter for Interfacing an
Insertable/Removable Digital Memory Apparatus to a Host Data
Port"), which is a continuation-in-part of U.S. patent application
Ser. No. 08/689,687, filed Aug. 13, 1996, now U.S. Pat. No.
5,877,975, issued Mar. 2, 1999 (Jigour and Wong,
"Insertable/Removable Digital Memory Apparatus and Method of
Operation Thereof"), all of which are hereby incorporated herein in
their entirety by reference thereto.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to adapters for interfacing an
external digital memory device to a host port, and more
particularly to adapters for interfacing an insertable and
removable digital memory device to a host port.
[0004] 2. Description of Related Art
[0005] A variety of add-on cards and modules for use in digital
systems such as personal computers ("PC") have enjoyed a measure of
success in various memory-intensive applications. Some of these
memory add-on cards use flash memory, and are known as flash PC
cards. Flash PC cards have become widely used for mass data storage
applications, and are a popular alternative for conventional add-on
card implemented non-volatile memory solutions such as rotating
hard disks and battery-backed SRAM, especially for notebook
computers, personal data assistants ("PDAs"), and some high-end
digital cameras. As an alternative to rotating hard disk PC cards,
flash PC cards are more rugged and space efficient, are silent,
consume less power, provide higher performance (in most cases), and
provide a removable form-factor. As an alternative to
battery-backed SRAM PC cards, flash PC cards typically offer
higher-densities and lower cost per bit and are not as limited by
reliability and temperature issues associated with batteries used
in the battery-backed SRAM PC cards.
[0006] FIG. 1 shows to scale the surface area of a number of high
capacity memory card types presently available. The surface area of
a flash PC card is shown at 100 in FIG. 1. Flash PC cards are
compliant with the Personal Computer Memory Card International
Association ("PCMCIA") standard, which specifies a form factor of
approximately 85.6 mm (3.37 inches) by 54 mm (2.126 inches), with a
thickness of either about 3 mm for a Type-I card or about 5 mm for
a Type-II card. The connector specified by the PCMCIA standard uses
68 pins organized in two rows of 34 pins each with 1.27 mm (50
mils) spacing between pins. The physical specifications for PC
cards are described in a publication of the Personal Computer
Memory Card International Association/JEIDA entitled PC Card
Standard, Volume 3: Physical Specification, Document No.
0295-03-1500, February 1995.
[0007] Flash PC cards typically have a high memory capacity of from
about 2 Megabytes to 85 Megabytes, although recently even higher
capacity cards have been introduced. Like hard-disks, flash PC
cards spend about 75 percent of operation time being read from and
25 percent being written to. The two primary PC card interface
types are ATA and Linear. PC cards that support the ATA interface
use an on-card ATA controller, which allows "plug and play"
compatibility between portable computers and PDAs. Linear flash
cards do not use a dedicated ATA controller and require software
drivers to implement file interface protocol.
[0008] While flash PC cards can provide sufficient amounts of
memory for a broad range of applications, they have not been widely
accepted for use in applications such as mobile and portable
electronics or for use in applications having significant cost
sensitivity. PC cards simply tend to be too large for many portable
applications such as pagers, voice recorders, mobile telephones,
and hand-held meters. PC cards are also too bulky and heavy for
carrying in a pocket or wallet, as would be desirable for many
consumer applications. Current PC cards are also quite expensive,
hence are offered generally as after market enhancements or
add-ons. PC cards can be made available at extremely high memory
capacities because of improved memory technology; however, such
extremely high memory capacities are in excess of what is optimal
for many mobile and portable applications. Moreover, although the
insertion lifetime of 68-pin PC card connectors, which is about
10,000 cycles, is generally adequate for portable computers and
PDAs, it is inadequate for other applications involving more
frequent insertion and removal of the storage media than
encountered in portable computing. In addition, the high number of
pins and the tendency of the narrow deep sockets on the PC cards to
collect foreign material increase the probability of failure,
especially if the PC cards are not carefully handled. Also, PC
cards have parallel busses, which are problematical since they
permit multiple signal transitions that cause system noise and
interference with wireless RF products. Some PC cards commonly
available use channel hot electron flash technology, which because
of its inherent high current demands tends to make erase/write
programming times lengthy and reduce effective battery lifetimes in
mobile and portable applications.
[0009] As the PCMCIA standard is not entirely suitable for small
portable devices, flash memory recently has been used in a variety
of removable devices having smaller form factors than the standard
PC card, including, for example, compact flash cards, miniature
cards, and solid state floppy disk cards ("SSFDC"). The surface
areas of these devices are illustrated at 110, 120 and 130
respectively in FIG. 1.
[0010] The compact flash card is a small format flash memory card
that was initially announced by SanDisk Corporation in 1994. The
form factor of the compact flash card is 36.times.43.times.3.3 mm,
and the surface area thereof, which is shown at 110 in FIG. 1, is
approximately 1/3 the surface area of the standard PC Card. The
card has a 50 pin connector that is a subset of the PC card
interface. The card supports the IDE/ATA interface standard by
means of an on-card ATA controller IC. Memory capacity in the range
of 2 Megabytes to 15 Megabytes is currently available, although
greater memory capacity devices are likely to be introduced. Both 5
volt and 3.3 volt power supplies are supported. A compact flash
card is interfaced to notebook computers and PDAs by inserting the
card into a special PC card adapter. The compact flash series is
described in a publication of the SanDisk Corporation entitled
Compact flash Series Preliminary Data Sheet, Document No.
80-11-00015, Rev. 1.0, October 1994.
[0011] The miniature card is a small format card that was initially
announced by Intel Corporation in 1995. The form factor of the
miniature card is 35.times.33.times.3.5 mm, and the surface area,
which is shown at 120 in FIG. 1, is approximately 25% the surface
area of the standard PC card. The miniature card has a 60 pin
Elastimeric connector rated at a minimum insertion lifetime of
5,000 cycles. The card supports a linear addressing range of up to
64 Megabytes of memory using a 16-bit data bus. Memory capacity in
the range of 2 Megabytes to 4 Megabytes is currently available,
although greater memory capacity devices are likely to be
introduced. The miniature card specification allows for flash, DRAM
and ROM memory types. Both 5 volt and 3.3 volt power supplies are
supported by the specification. A miniature card is interfaced to
notebook computers and PDAs that support the standard PC card
interface with a special PC card adapter. A miniature card
specification is described in Miniature Card Specification, Release
1.0, February 1996, available from Intel Corporation of Santa
Clara, Calif.
[0012] The solid state floppy disk card, or SSFDC, is a small
format card initially announced by Toshiba Corporation in 1995. The
form factor of the SSFDC card is 45.times.37.times.0.76 mm, and the
surface area thereof, which is shown at 120 in FIG. 1, is
approximately 36% the surface area of the standard PC card. The
SSFDC has 22 flat contact pads, some of which are pads for both
address and data input and output as well as for command inputs.
The card specification is dedicated to byte serial NAND-type flash
memory. Memory capacity of 2 Megabytes is currently available,
although memory capacity in the range of 512 kilobytes to 8
Megabytes is anticipated. The specification accommodates 5 volt or
3.3 volt power supplies. An SSFDC is interfaced to notebook
computers and PDAs that have the standard PC card interface with a
special PC card adapter. An illustrative device is type TC5816ADC,
which is described in Preliminary TC5816ADC Data Sheet No.
NV16030496, April 1996, available from Toshiba America Electronic
Components, Inc. of Irvine, Calif. The device is said to be
suitable for such applications as solid state file storage, voice
recording, image file memory for still cameras, and other systems
which require high capacity, non-volatile memory data storage.
[0013] Seimens Components of Cupertino, Calif. has described a
device known as MultiMediaCards, or MMC; see Portable Design, July
1996, p. 23 et seq. The form factor of the MMC package is
37.times.45.times.1.4 mm, and the surface area, which is shown at
140 in FIG. 1, is approximately 36% that of the standard PC card.
The MMC package has 6 edge-mounted contact pads with an insertion
lifetime of 10,000 cycles, and uses a serial bus. Initially, MMCs
are expected to be offered with a choice of 16 Megabit or 64
Megabit ROM memory, but is reported to be teaming up with
undisclosed partners to put flash memory on its MMC cards. The
specification accommodates a 3.3 volt power supply. The device is
said to be suitable for such applications as video games, talking
toys, automobile diagnostics, smart phones (tailored operating
systems or special programs), PDAs (tailored operating systems or
special programs), and notebooks through a PDA adapter.
[0014] Some low memory capacity card formats have enjoyed a measure
of success in certain specific applications. FIG. 2 shows form
factors 210 and 220 of two commercially successful low memory
bandwidth card formats known as the IC card format and the SIM card
format, respectively. The form factors 210 and 220 are to scale
with the form factors 100, 110, 120 and 130 of FIG. 1.
[0015] The Integrated Circuit (IC) card format and the similar
Identification (ID) card format, commonly known as smart cards,
were introduced in the mid 1980's, and have been standardized by
the International Organization for Standardization (ISO); see
International Organization for Standardization, Identification
Cards-Integrated Circuit Cards with Contacts, Part 1: Physical
Characteristics, Document No. ISO 7816-1, July 1987; International
Organization for Standardization, Identification Cards-Integrated
Circuit Cards with Contacts, Part 2: Dimensions and Location of
Contacts, Document No. ISO 7816-2, May 1988; and International
Organization for Standardization, Identification Cards-Integrated
Circuit Cards with Contacts, Part 3: Electronic Signals and
Transmission Protocols, Document No. ISO 7816-3, September 1989.
Smart cards are credit card sized and typically contain a
microcontroller with a small amount of EEPROM memory, typically 256
to 8K bits. The surface area of the smart card is shown at 210 in
FIG. 2. The length and width of the smart card is nearly identical
with the length and width of the PC card, but the smart card is
much thinner. The cards are popular in Europe and are making
inroads into the US market. Primary applications are smart
telephone calling cards and stored value cards, the later
application being promoted by credit card companies like Visa and
Master card as a replacement for paper currency. IC and ID cards
have a simple contact pattern of eight flat contact pads designated
C1-C8 of which only six are used. Contact signal assignments are
C1=V.sub.CC (supply voltage), C2=RST (reset), C3=CLK (clock
signal), C4=Reserved, C5=GND (ground), C6=V.sub.PP (programming
voltage), C7-I/O (data input/output) and C8=Reserved. Due to their
popularity in Europe, a great infrastructure of connectors and
readers is already established for IC and ID cards.
[0016] Another low memory capacity card format is known as the
Subscriber Identification Module ("SIM"), which is used in
conjunction with mobile telephones based on the Global System for
Mobile Communications ("GSM") standard. The SIM specification is
set forth in a publication of the European Telecommunication
Standard Institute entitled European Digital Cellular
Telecommunication System, Global System for Mobile Communications,
Phase 2: Specification of Subscriber Identity Module-Mobile
Equipment Interface, Document No. GSM11.11, Reference
(RE/SMG)-091111PR3, ICS 33.060.50, December 1995. The form factor
of the SIM is 25 mm.times.15 mm.times.0.76 mm, and the surface area
thereof, which is shown at 220 in FIG. 2, is much smaller than the
standard PC card. SIMs offer only a very limited amount of memory,
typically less than one kilobit. However, this small amount of
memory is sufficient to provide a GSM mobile phone with secure
identification of the GSM subscriber, and may also hold a small
amount of data for call metering, phone number storage, and in some
cases very short data messages (less than a few hundred bytes of
data). The SIM uses the same 8 pad contact pattern as the IC card,
but only five of the pads are required for V.sub.CC, RST, CLK, GND,
and I/O. The plug-in SIM typically is housed in a small hinged
smart card connector similar to the type CCM03 available from ITT
Cannon Corporation of Santa Ana, Calif. The small form factor
allows the GSM SIM to be placed inside the phone as a plug-in
module. Because the GSM SIM typically is removed only if a
different GSM phone is to be used, GSM SIM connectors typically are
designed for fewer insertion/removal cycles than normally
experienced with IC and ID cards.
[0017] Other memory technologies have not been widely used in
insertable/removable memory modules and cards because of their
inherent shortcomings relative to such successful technologies as
flash. For example, battery-backed SRAM or DRAM memories require
supplemental battery power when the main power is removed, while
flash memory is non-volatile (no battery is needed) and is more
reliable over temperature. Flash memory is available in higher
densities and at lower cost/bit than SRAM and EEPROM memory, and is
cost-competitive with DRAM memory.
[0018] Despite advances in the art, a need still exists for a
memory card or module that can store and be used to transfer large
amounts of digital information such as commonly encountered in
audio, data and image applications, yet be inexpensive to
manufacture, compatible with existing standards, easy to store,
convenient to insert and remove from its host, rugged and durable
enough to withstand numerous insertion/removal cycles, and require
minimal hardware interface overhead.
SUMMARY OF THE INVENTION
[0019] One embodiment of the present invention is an adapter to
interface a digital media device to a port of a host, the adapter
comprising a host port connector, a socket for receiving a digital
media device, and a circuit mapping the host port connector to the
socket.
[0020] Another embodiment of the present invention is an adapter as
in the previous embodiment, but in which the host port connector
comprises a serial data conductor, a power conductor, a ground
conductor, and a clock conductor. The serial data conductor, the
power conductor, the ground conductor, and the clock conductor are
mapped to respective contact pads in the socket. The socket may
conform to any protocol, including the SPI protocol.
[0021] Another embodiment of the present invention is an adapter
for interfacing a memory device to a port of a host, the adapter
comprising a host port connector, a socket having a plurality of
surface pad contacts and an orifice for receiving a generally
planar memory device having a plurality of surface pads, and a
circuit mapping the host port connector to the surface pad contacts
of the socket.
[0022] Yet another embodiment of the present invention is an
adapter as in the previous embodiment, but in which the host port
connector comprises a serial data conductor, a power conductor, a
ground conductor, and a clock conductor. The serial data conductor,
the power conductor, the ground conductor, and the clock conductor
are mapped to respective contact pads in the socket. The socket may
conform to any protocol, including the SPI protocol.
[0023] Another embodiment of the present invention is an adapter
for interfacing a memory device to a port of a host, the adapter
comprising a host port connector comprising a serial data contact,
a clock contact, and a ground contact; a socket having a plurality
of surface pad contacts and an orifice for receiving a generally
planar memory device having a plurality of surface pads; and a
circuit mapping the data contact, the clock contact, and the ground
contact of the host port connector to respective ones of the
surface pad contacts of the socket. The surface pad contacts of the
socket may conform to any protocol, including the SPI and NXS
protocols.
[0024] Another embodiment of the present invention is an adapter
for interfacing a memory device to a port of a host, the adapter
comprising a host port connector comprising a serial data contact,
a clock contact, and a ground contact; a socket having a plurality
of contacts and an orifice for receiving a generally planar memory
device about 15 mm wide; and a circuit mapping the data contact,
the clock contact, and the ground contact of the host port
connector to respective ones of the contacts of the socket.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In the drawings, in which like reference characters indicate
like parts:
[0026] FIG. 1 is a schematic view of the surface area profile of a
variety of high capacity prior art add-on cards;
[0027] FIG. 2 is a schematic view of prior art smart card and SIM
module surface area profiles;
[0028] FIG. 3 is a perspective view of a family of digital media
devices in accordance with the present invention;
[0029] FIG. 4 is a schematic view of the surface area profiles of
various digital media devices in accordance with the present
invention;
[0030] FIGS. 5, 6 and 7 are schematic views of contact pad arrays
in accordance with the present invention;
[0031] FIG. 8 is a top plan view of a socket for receiving digital
media devices of the FIG. 3 family;
[0032] FIG. 9 is a cross-sectional view of the socket of FIG.
8;
[0033] FIG. 10 is a cross-sectional view of a digital media device
inserted into the socket of FIG. 8;
[0034] FIGS. 11, 12, 13 and 14 are block schematic diagrams of
signal and power connections for exemplary interfaces for the
digital media devices of the FIG. 3 family;
[0035] FIG. 15 is a cross-sectional view of a surface mount digital
media device having two surface-mounted packaged integrated
circuits;
[0036] FIG. 16 is a cross-sectional view of a chip-on-board-modular
digital media device having one chip;
[0037] FIG. 17 is a cross-sectional view of a chip-on-board-modular
digital media device having two chips;
[0038] FIG. 18 is a cross-sectional view of a chip-on-board-direct
digital media device having two chips;
[0039] FIGS. 19-23 are pictorial views of various applications for
the digital media devices in the FIG. 3 family; and
[0040] FIG. 24 is a schematic diagram of an adapter for interfacing
a standard PC parallel port to a digital media device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0041] Digital media means insertable/removable memory media for
storing and transferring large digital files, especially audio,
data and image files in personal, portable, industrial and mobile
environments. Digital media storage typically involves a higher
percentage of erase/write accesses than code storage and ordinary
data and mass storage, typically about 50 percent read and 50
percent erase/write ratio. The storage requirement typically is
high capacity, i.e. about one Megabit or greater. For example, a
one Megabit flash device might store 1-2 minutes of digital voice
recording, a 10 page fax, or 10-20 medium resolution compressed
digital camera pictures. Preferably, digital media supports read,
erase, and write at either 5 volt or 3 volt supply levels, and
contains small sectors that can be programmed quickly to
efficiently use battery-power and to keep pace with high-speed
portable and mobile applications. Examples of media elements stored
or transferred include voice and sound clips, facsimile, pictures,
writing, drawing, scanned images, maps, e-mail, data logging,
downloadable code, and general data files. A few examples of
emerging digital media storage applications include digital
cameras, solid-state voice recorders, portable scanners and barcode
readers, voice/data pagers, cellular phone answering machines,
portable pen-based tablets, hand-held terminals and meters, and
portable data acquisition equipment.
[0042] FIG. 3 is a perspective view of a family 300 of removable
digital media devices 310, 320, 330, 340, 350 and 360, each of
which when plugged into a host permits the host to store data in it
or to retrieve data from it. Preferably, the form factors of the
digital media devices in the family 300 and the connector system
used by the digital media devices are compact for minimizing the
volume of space occupied in portable devices and for easy storage.
Some embodiments, illustratively digital media devices 310, 320,
330, 350 and 360 provide an elongated compact form factor that
provides easy and firm grasping for insertion and removal. The
digital media devices of the family 300 have respective body
portions 312, 322, 332, 342, 352 and 362 preferably of a rigid or
semi-rigid material such as mylar, poly-vinyl chloride ("PVC") or
PVCA material, which is commonly used in smart cards and modules,
or FR4 epoxy glass, which is commonly used for printed circuit
boards. Preferably, the digital media devices of the family 300 use
serial memory requiring few power and signal lines, so that few
electrical contacts are required. In particular, a small number of
durable contact pads form respective contact arrays 314, 324, 334,
344, 354 and 364 on the digital media devices 310, 320, 330, 340,
350 and 360, which in conjunction with corresponding contact pads
mounted into a suitable socket provide for easy and convenient
insertion and removal and for robust and reliable electrical
contact over a long insertion lifetime. Preferably, the digital
media devices of the family 300 incorporate flash memory, which
permits low voltage operation, low power consumption, and high
capacity non-volatile data storage. Preferably, the digital media
devices of the family 300 are fabricated using surface mount
techniques, of which the digital media devices 310 and 320 are
illustrative, or particularly inexpensive "Chip on Board" ("COB")
techniques, of which the digital media devices 330, 340, 350 and
360 are illustrative.
[0043] Preferably, the form factors of the digital media devices in
the family 300 are compact for easy storage and transportation and
for minimizing "insertion volume" in a host such as a laptop
computer or PDA. Insertion volume is the volume required to house a
card or module, or rather the connector of the card or module and
as much of the card or module as is required to be contained by the
host. Some family members provide an elongated compact form factor
that provides easy and firm grasping for insertion and removal, as
well as space for additional memory ICs or chips. Other family
members are of a length comparable with the length of certain
common battery types such as AA and AAA batteries, and are therefor
capable of insertion into the battery compartments of personal,
portable and mobile equipment.
[0044] Although generally shown as having a rectangular shape, the
digital media devices of the family 300 may be made in other
shapes. For example, the digital media device 350 has a key-like
shape which provides not only convenient handling but also more
surface area for additional memory circuits and for the
manufacturer's logo, use instructions, user written notes, and the
like. The comers of the digital media devices of the family 300 may
be rounded if desired.
[0045] FIG. 4 shows illustrative surface area profiles 410, 420 and
430 of various digital media devices, which are at the same scale
as the various surface area profiles shown in FIGS. 1 and 2. As
will be appreciated by comparing the surface area profiles 410, 420
and 430 with the various surface are profiles for flash memory
devices shown in FIG. 1, the digital media devices having the
surface area profiles 410, 420 and 430 have numerous advantages,
even while providing memory capacity that is comparable with most
other high capacity cards and comparable even with PC cards at the
low end of their typical capacity range, yet ideally suited to
digital media storage applications. For example, the surface area
profile 420 is only about 15% the surface area profile 100 of the
PCMCIA form factor and has a relatively small insertion volume
requirement, and even the profile 410 is only about 18% the surface
area profile 100 of the PCMCIA form factor and also has a
relatively small insertion volume requirement. Compare the surface
area profiles 410 and 420 with, for example, the surface area
profile 110 of the compact flash form factor, the surface area
profile 120 of the miniature card form factor, and the surface area
profile 130 of the SSFDC form factor. The compact flash surface
area profile 110 is about 33% the surface area profile 100 of the
PCMCIA form factor and has a relatively large insertion volume
requirement. The miniature card surface area profile 120 is about
25% the surface area profile 100 of the PCMCIA form factor and has
a relatively moderate insertion volume requirement. The SSFDC
surface area profile 130 is about 36% the surface area profile 100
of the PCMCIA form factor and has a relative large insertion volume
requirement.
[0046] The long form factor 420 shown in FIG. 4 has a width of 15
mm, a length of 45 mm, and a thickness of 0.76 mm. Long form factor
410, which is compatible with smart card manufacturing techniques
because its length is the same as the width of a smart card, has a
width of 15 mm, a length of 54 mm, and a thickness of 0.76 mm. The
short form factor 430 shown in FIG. 4 has a width of 15 mm, a
length of 25 mm, and a thickness of 0.76 mm. The long and short
form factor dimensions are illustrative, and the optimal size of
the form factors suitable for the digital media device family 300
is influenced by several factors, including, for example, the size
of the host, the size of the electrical contact array required, the
need for sufficient body surface and a suitable shape for a user to
grasp the device for insertion, removal, and transport, convenience
of transport and storage, and compatibility for insertion into
compartments such as battery compartments commonly provided in
personal, portable and mobile equipment. The choice of form factor
within the range of acceptable form factors is also influenced by
other factors, including, for example, whether sufficient surface
on the body is required for a user to grasp the digital media
device for insertion and removal without touching the electrical
contact array, which tends to favor a longer form factor; and
whether the digital media device is intended for cost-sensitive
applications, in which case the availability of low cost high
volume manufacturing techniques is important. An example of the
latter is a digital media device having a length equal to the width
of a standard ISO smart IC card, which permits manufacturing
equipment suitable for standard ISO smart cards to be used in the
manufacture of the digital media device. The thickness of the
digital media devices in the family 300 preferably achieves
sufficient rigidity to permit good control over insertion and
removal, and to prevent damage to the integrated circuit due to
device stress under normal use. The rigidity requirements may be
relaxed where the die is small or is otherwise protected, as where
the die is mounted using COB packaging techniques in which the die
is mounted on a rigid substrate and encased with epoxy material.
Illustratively, where the media device is made from PVC, PVCA, or
FR4 epoxy glass, a convenient thickness is about 0.8 mm.
[0047] A small number of durable contact pads form respective
contact arrays 314, 324, 334, 344, 354 and 364 on the digital media
devices 310, 320, 330, 340, 350 and 360, which in conjunction with
corresponding contact pads mounted into a suitable socket provide
for easy and convenient insertion and removal and for robust and
reliable electrical contact. Contact pads are preferred to pins and
sockets, since they are more durable and do not clog. The contact
pads both in the digital media device and in its corresponding
socket are flat or generally flat and lie in a generally planar
major surface of the digital media device.
[0048] The number of contact pads in the array preferable is kept
low, thereby permitting both a small form factor with the
advantages mentioned above, as well as large contact pads to ensure
durability and reliable electrical contact over many
insertion-removal cycles. Contact pads disposed on a flat surface
are preferred to edge pads since surface mounted pads do not trap
dirt, lint, and other foreign objects, and effectively and reliably
self-clean upon both insertion and removal. Surface mounted pads
are more robust that the pin and socket connectors specified for
PCMCIA cards, which have the further disadvantage of readily
trapping dirt, lint, and other foreign objects.
[0049] Preferably, the electrical contacts of the digital media
devices in the family 300 conform to the physical form of the
aforementioned eight pin ISO IC card standard commonly used for
smart cards and GSM SIMs, although more or fewer electrical
contacts may be used if desired, consistent with the desired
interface scheme, memory capacity, form factor, and insertion
lifetime. Connectors that physically conform to the ISO IC card
standard are advantageous in that they are readily available and
simple and inexpensive to manufacture. The insertion lifetime of
such contact pads is approximately 30,000 insertion/removal cycles
or greater, which is a function of the thickness and composition of
the contact pad material.
[0050] Digital media devices based on the ISO IC card standard are
shown in FIGS. 5, 6 and 7. Illustratively, the digital media device
500 of FIG. 5 is 15 mm wide and 45 mm long. The contact pad array
510 is set back from the head of the digital media device 500 by
3.0 mm, and from the side of the digital media device 500 by 2.5
mm. Each of the contact pads 511, 512, 513, 514, 515, 516, 517 and
518 is 2.25 mm by 4.0 mm in size. Typically, gaps between adjacent
contact pads 511 and 512, 512 and 513, 513 and 514, 515 and 516,
516 and 517, and 517 and 518 are about 0.33 mm, while pads 511 and
515, 512 and 516, 513 and 517, and 514 and 518 are about 3.5 mm.
The contact pads 511-518 are made of any suitable contact pad
material, such material being well known in the art. Pads 525 and
526, which are made of any suitable contact pad material, are write
protect pads. While shown near the center of one edge of the
digital media device 500, they may be located in any convenient
place such as, for example, near one of the comers at the tail of
the digital media device 500. A hole 530 is provided in the tail of
the digital media device 500 to facilitate removal thereof from a
socket.
[0051] Illustratively, the digital media device 600 of FIG. 6 is 15
mm wide and 45 mm long. The contact pad array 610 is set back from
the head of the digital media device 600 by 3.0 mm, and from the
side of the digital media device 600 by 2.5 mm. Each of the contact
pads 611, 612, 613, 614, 616, 617 and 618 is 2.25 mm by 4.0 mm in
size. The contact pad 615 has a portion that is 2.25 mm by 4.0 mm
in size, but also has a first extension portion that extends about
3.5 mm toward contact pad 611, and a second extension portion that
is just less than 3.5 mm wide and lies between pads 612 and 616,
pads 613 and 617, and pads 614 and 618, which are spaced 3.5 mm
from one another. Typically, gaps between adjacent portions of the
contact pads 611-618 are about 0.33 mm. The contact pads 611-618
are made of any suitable contact pad material, such material being
well known in the art. Pads 625 and 626, which are made of any
suitable contact pad material, are write protect pads. While shown
near the center of one edge of the digital media device 600, they
may be located in any convenient place such as, for example, near
one of the comers at the tail of the digital media device 600. A
hole 630 is provided in the tail of the digital media device 600 to
facilitate removal thereof from a socket.
[0052] Illustratively, the digital media device 700 of FIG. 7 is 15
mm wide and 45 mm long. The contact pad array 710 is set back from
the head of the digital media device 700 by 3.0 mm, and from the
sides of the digital media device 700 by 2.5 mm. Each of the
contact pads 711, 712, 713, 714, 717 and 718 is 2.25 mm by 4.0 mm
in size. The contact pad 715 also has a portion that is 2.25 mm by
4.0 mm in size, but has a first extension portion that extends
about 3.5 mm toward contact pad 711, and a second extension portion
that is 1.75 mm wide and lies between pads 712 and 716. Pads 713
and 717 and pads 714 and 718 are spaced 3.5 mm from one another,
and pads 712 and 716 are spaced 4.5 mm from one another. Typically,
gaps between adjacent portions of the contact pads 711-718 are
about 0.33 mm wide, although the edge of the pad 716 toward the
head of the digital media device 700 is spaced 2.75 mm from the
second extension portion of the pad 715. The contact pads 711-718
are made of any suitable contact pad material, such material being
well known in the art. Pads 725 and 726, which are made of any
suitable contact pad material, are write protect pads. While shown
near the center of one edge of the digital media device 700, they
may be located in any convenient place such as, for example, near
one of the corners at the tail of the digital media device 700. A
hole 730 is provided in the tail of the digital media device 700 to
facilitate removal thereof from a socket.
[0053] A socket 800 for receiving a digital media device 1000,
which is representative of a device in the device family 300, is
shown in FIGS. 8, 9 and 10. The socket base 810 is made of any
suitable electrically insulative, durable and heat-resistant
material, such material being well known in the art. Eight
electrical contact pads 821, 822, 823, 824, 825, 826, 827 and 828
of any suitable material are molded into and held in place by the
base 810, such material being well known in the art. Alternatively,
in single-chip cards and for the NXS protocol described below, six
contact pads are sufficient for the digital media device so that
contact pads 824 and 828 of the socket 800 may be eliminated if
desired. An end of each of the pads 821-828 is brought out beyond
the base 810 for connection to external circuitry. As more clearly
visible in the cross-section of FIG. 9, the other end of each of
the pads 821-828 is bent up from the base 810 and has a springy
characteristic to press against and engage a contact pad on the
digital media device 1000. A U-shaped envelope 830 is attached to
the base 810 during the molding process, and rises therefrom over
the bent ends of the pads 821-828 to provide a cavity for receiving
the digital media device 1000.
[0054] FIG. 10 shows the digital media device 1000 (die and
interconnections are omitted for clarity) inserted into the socket
800. The bent ends of the pads 821-828, e.g. pads 822 and 826 are
shown, are stressed by the inserted digital media device 1000 and
push it against the envelope 830, thereby holding it firmly in
place and contacting pads on the digital media device 1000, e.g.
pads 1022 and 1026. Weak interlocks (not shown) of any suitable
type well known in the art may be provided on the socket 800 and on
the digital media device 1000 if desired to provide a discernible
tactile response when the digital media device 1000 is properly
seated.
[0055] The socket shown in FIG. 8, FIG. 9 and FIG. 10 is
illustrative, and suitable sockets for receiving the digital media
device 1000 are readily available. For example, standard sockets
conforming to the eight pin ISO IC card standard are suitable if
modified to guide the relatively narrower digital media device 1000
into engagement with the electrical contacts of the socket. The ISO
IC sockets are available from various manufacturers, including ITT
Cannon Corporation of Santa Ana, Calif.; see CCM Smart Card
Connectors Catalog, Document No. CCM 7/94-A, July 1994. A suitable
socket from this manufacturer is part number CCC 03 3504. The six
pad SIM sockets are also suitable for receiving the digital media
device 1000 where only six contact pads are active. SIM socket
types having pivot covers can also be used provided they are
modified by removal of a siderail to permit side insertion. Six pad
SIM sockets and custom eight pad SIM sockets are available from
various manufacturers, including Amphenol of Hamden, Conn.
[0056] Preferably, the digital media devices of the family 300
incorporate high density serial flash memory, which requires few
power and signal lines and permits low voltage operation, low power
consumption, and high capacity non-volatile data storage. A
suitable serial flash memory circuit is disclosed in U.S. Pat. No.
5,291,584, issued Mar. 1, 1994 to Challa et al. and entitled
"Method and Apparatus for Hard Disk Emulation," which is hereby
incorporated herein by reference in its entirety. One type of
serial flash memory includes one or more flash memory arrays, one
or more row decoders, column selects, page latches, data shift
registers, sense amps, row address shift registers, and control
logic and data buffers.
[0057] Other serial standards and specifications may also be
suitable other than the specification set forth in the
aforementioned Challa et al. patent, including, for example, SPI,
I2C, COPS and MICROWIRE. However, serial flash memory of the type
disclosed in the aforementioned Challa et al. patent is
particularly advantageous because it requires a minimum number of
electrical contacts, is capable of being manufactured at high
memory densities, is of relatively small die size, and has low
power consumption. For example, the Challa bit-serial flash memory
requires only four outside connections, viz. V.sub.CC, ground, data
input/output ("I/O"), and clock. Other connections may be desirable
in some applications or for other types of flash memory, including,
for example, chip select, write protect, ready/busy, and memory
test. Typical densities available with current process technology
are in the range of 1 Megabit to 16 Megabits, and densities are
expected to increase with improvements in process technology. A
memory density of, for example, 8 Megabits fabricated with
conventional 0.7 .mu.m process technology typically is presently
available.
[0058] The contact pads of the digital media devices in the family
300 are assigned signal and power functions depending on the
interface selected. Preferred serial interface protocols are the
Nexcom Serial Interface protocol, or NXS protocol, which is
described in the aforementioned Challa et al. patent and specifies
a two-wire interface, viz. Clock and Data I/O; and the Serial
Peripheral Interface ("SPI") protocol, which specifies a four-wire
interface, viz. Clock, Data In, Data Out, and Chip Select. The NXS
and SPI protocols are illustrative, and other protocols may be used
if desired. While the use of eight contact pads is described, six
pads would be entirely satisfactory for some applications and the
interface protocols would be adjusted accordingly.
[0059] One set of illustrative pad assignments for the digital
media device 700 using the NXS protocol (pad assignments for the
digital media devices 500 and 600 are analogous) are as follows:
V.sub.CC at pad 711, NC (no connection) at pad 712, SCK at pad 713,
NC at pad 714, GND and DT (card detect) at pad 715 (the digital
media device 500 does not support DT), NC/WP.backslash.and
DT.backslash. at pad 716, DIO at pad 717, and NC at pad 718.
[0060] FIG. 11 is a block schematic diagram of illustrative
electrical connections suitable for this set of illustrative pad
assignments. V.sub.CC and ground are furnished to an NXS protocol
digital media device 1110, which includes, illustratively, the
contact pad array 710 (contact pad arrays 510 and 610 are
analogous) through respective contact pads 711 and 715. The digital
media device 1110 includes two NXS protocol memory integrated
circuits 1112 and 1114 (alternatively, the digital media device
1110 may contain one memory integrated circuit or more than two
memory integrated circuits). A controller 1100, which is any
suitable controller, including, for example, general purpose
microcontrollers, digital signal processors, and
application-specific integrated circuit logic, furnishes its clock
signal SCK to the SCK ports of the NXS protocol memory integrated
circuits 1112 and 1114 through the contact pad 713, and its data
signal SIO to the DIO ports of the NXS protocol memory integrated
circuits 1112 and 1114 through the contact pad 717. As further
described in the aforementioned Challa et al. patent, the NXS
protocol supports multiple memory integrated circuits by having
each memory integrated circuit receive chip select address
information through the serial terminal, decode the chip select
address information using on-board logic, and self-activate when
the decoded address matches the IC's static address. The static
addresses of the integrated circuits 1112 and 1114 are established
by connecting the A0, A1, A2 and A3 terminals to V.sub.CC and
ground, as appropriate. Resistor 1102 is a pull-up resistor having
a value of, for example, 10,000 ohms, and is useful in card
insertion/removal detection. The resistor 1102 is connected between
a detect control port DC and a write protect-card detect port
WP.backslash.-DT.backslash. of the controller 1100. The write
protect-card detect port WP.backslash.-DT.backslash. of the
controller 1100 contacts pad 716 when the digital media card is
inserted into it's socket.
[0061] Another set of illustrative pad assignments for the digital
media device 700 using the NXS protocol pad assignments for the
digital media devices 500 and 600 are analogous) are as follows:
V.sub.CC at pad 711, A3-1 at pad 712, SCK at pad 713, A3-0 at pad
714, GND and DT (card detect) at pad 715 (the digital media device
500 does not support DT), WP.backslash.-DT.backslash. and A2 at pad
716, SIO at pad 717, and A1 at pad 718.
[0062] FIG. 12 is a block schematic diagram of illustrative
electrical connections suitable for this set of illustrative pad
assignments. V.sub.CC and ground are furnished to an NXS protocol
digital media device 1210, which includes, illustratively, the
contact pad array 710 (contact pad arrays 510 and 610 are
analogous) through respective contact pads 711 and 715. The digital
media device 1210 includes two NXS protocol memory integrated
circuits 1212 and 1214 (alternatively, the digital media device
1210 may contain one memory integrated circuit or more than two
memory integrated circuits). A controller 1200, which is any
suitable controller, including, for example, general purpose
microcontrollers, digital signal processors, and
application-specific integrated circuit logic, furnishes its clock
signal SCK to the SCK ports of the NXS protocol memory integrated
circuits 1212 and 1214 through the contact pad 713, and its data
signal SIO to the SI and SO ports of the NXS protocol memory
integrated circuits 1212 and 1214 through the contact pad 717. As
further described in the aforementioned Challa et al. patent, the
NXS protocol supports multiple memory integrated circuits by having
each memory integrated circuit receive chip select address
information through the serial terminal, decode the chip select
address information using on-board logic, and self-activate when
the decoded address matches the IC's static address. The static
addresses of the integrated circuits 1212 and 1214 are established
by connecting the A0 terminals to V.sub.CC and ground, as
appropriate. The A1 and A3-0 and A3-1 terminals are brought out for
test purposes, or optionally may be tied high or low. The A2
terminal it tied high through resistor 1202, which is a pull-up
resistor having a value of, for example, 10,000 ohms, and is useful
in card insertion/removal detection. The resistor 1202 is connected
between a detect control port DC and a write protect-card detect
port WP.backslash.-DT.backslash. of the controller 1200. The write
protect-card detect port WP.backslash.-DT.backslash. of the
controller 1200 contacts pad 716 when the digital media card is
inserted into it's socket.
[0063] One set of illustrative pad assignments for the digital
media device 700 using the SPI interface 700 are as follows:
V.sub.CC at pad 711, CS0.backslash. at pad 712, SCK at pad 713,
CS1.backslash. at pad 714, GND and DT at pad 715 (the digital media
device 500 does not support DT), WP.backslash. and DT.backslash. at
pad 716, SIO at pad 717, and RB (Ready/Busy) at pad 718.
[0064] FIG. 13 is a block schematic diagram of illustrative
electrical connections suitable for this set of illustrative pad
assignments. V.sub.CC and ground are furnished to an SPI protocol
digital media device 1310, which includes, illustratively, the
contact pad array 710 (contact pad arrays 510 and 610 are
analogous) through respective contact pads 711 and 715. The digital
media device 1110 includes two SPI protocol memory integrated
circuits 1312 and 1314 (alternatively, the digital media device
1310 may contain one memory integrated circuit or more than two
memory integrated circuits). A controller 1300, which is any
suitable controller, furnishes its clock signal SCK to the SCK
ports of the SPI protocol memory integrated circuits 1312 and 1314
through the contact pad 713, and its data signal SIO to the SIO
port of the SPI protocol memory integrated circuits 1312 and 1314
through the contact pad 717. The SPI protocol supports multiple
memory integrated circuits by having each memory integrated circuit
activated by a specific chip select signal. Hence, memory
integrated circuit 1312 is selected by signal CS0.backslash.
applied through pad 712, and memory integrated circuit 1314 is
selected by signal CS1.backslash. applied through pad 714. Resistor
1302 is a pull-up resistor having a value of, for example, 10,000
ohms, and is useful in card insertion/removal detection. The
resistor 1302 is connected between a detect control port DC and a
write protect-card detect port WP.backslash.-DT.backslash. of the
controller 1300. The write protect-card detect port
WP.backslash.-DT.backslash. of the controller 1300 contacts pad 716
when the digital media card is inserted into it's socket. A
ready-busy port RB of the controller 1300 is connected to
corresponding ports of the memory integrated circuits 1312 and 1314
through pad 718.
[0065] Another set of illustrative pad assignments for the digital
media device 700 using the SPI interface 700 are as follows:
V.sub.CC at pad 711, CS1.backslash. at pad 712, SCK at pad 713,
CS0.backslash. at pad 714, GND and DT at pad 715 (the digital media
device 500 does not support DT), WP.backslash. and DT.backslash. at
pad 716, SO at pad 717, and SI at pad 718.
[0066] FIG. 14 is a block schematic diagram of illustrative
electrical connections suitable for this set of illustrative pad
assignments. V.sub.CC and ground are furnished to an SPI protocol
digital media device 1410, which includes, illustratively, the
contact pad array 710 (contact pad arrays 510 and 610 are
analogous) through respective contact pads 711 and 715. The digital
media device 1410 includes two SPI protocol memory integrated
circuits 1412 and 1414 (alternatively, the digital media device
1410 may contain one memory integrated circuit or more than two
memory integrated circuits). A controller 1400, which is any
suitable controller, furnishes its clock signal SCK to the SCK
ports of the SPI protocol memory integrated circuits 1412 and 1414
through the contact pad 713, and its data signals SO and SI to the
SO and SI ports of the SPI protocol memory integrated circuits 1412
and 1414 through the contact pads 717 and 718, respectively. The
SPI protocol supports multiple memory integrated circuits by having
each memory integrated circuit activated by a specific chip select
signal. Hence, memory integrated circuit 1412 is selected by signal
CS0.backslash. applied through pad 714, and memory integrated
circuit 1414 is selected by signal CS1.backslash. applied through
pad 712. Resistor 1402 is a pull-up resistor having a value of, for
example, 10,000 ohms, and is useful in card insertion/removal
detection. The resistor 1402 is connected between a detect control
port DC and a write protect-card detect port
WP.backslash.-DT.backslash. of the controller 1400. The write
protect-card detect port WP.backslash.-DT.backslash. of the
controller 1400 contacts pad 716 when the digital media card is
inserted into it's socket. Ready-busy ports of the memory
integrated circuits 1412 and 1414 are not used, and are factory
programmed as no-connect. However, they are tied to GND and VCC
respectively.
[0067] Optional write protection is achieved using the GND-DT and
WP.backslash.-DT.backslash. ports. While the following functional
description pertains to the NXS controller 1100 and digital media
device 700, the NXS controller 1200, the SPI controllers 1300 and
1400, and digital media devices 500 and 600 function in an
analogous manner. When write protection is desired, pad 726, which
is electrically identical to pad 716, is shorted to pad 725, which
is electrically identical to pad 715, using, for example,
conductive tape, a conductive edge clip, or an integrated
mechanical switch. When the digital media card 700 is inserted into
a socket, the WP-DT port of the controller is pulled down, which is
sensed as write protect by the controller 1110.
[0068] Other write protection techniques may be used if desired,
including the provision of notches in the body of the digital media
device which can be closed using either tape or a slideable tab to
indicate write protect or write enable, as desired. Such techniques
are well known in the art.
[0069] The digital media device 700 supports a card detection
function with its unique arrangement of pads in the pad array 710.
While the following functional description pertains to the NXS
controller 1100, the NXS controller 1200 and the SPI controllers
1300 and 1400 controller 1200 function in an analogous manner
unless otherwise mentioned. The detect control or DC port of the
controller 1100 goes high at particular times to interrogate the
socket. Illustratively, the DC port is periodically brought high
for a brief period. If the card detect port or DT port of the
controller 1100 is pulled up, it is an indication that no card is
present in the socket or that a properly inserted card is present
in the socket and is not write protected. A read is then attempted
by sending a read opcode and static address on the port SIO for NXS
protocol devices or by sending a chip select signal on
CS0.backslash. or CS1.backslash. as appropriate and a read opcode
on the port SIO (port SI of the controller 1400) for SPI protocol
devices, and clocking port SCK. If the read is successful, a
digital media device is properly installed and a transaction
begins. If the read is not successful, no card is present. However,
if the DT.backslash. port is not pulled up, it is an indication
that a card is present in the socket but is not properly inserted
or that a properly inserted card is present in the socket and is
write protected. A read is then attempted. If the read is
successful, a write-protected digital media device is properly
installed and a transaction begins. If the read is unsuccessful, an
improperly inserted card is present and the controller 1100 signals
an insertion error.
[0070] The digital media device 700 supports a card removal
detection function with its unique arrangement of pads in the pad
array 710. While the following functional description pertains to
the NXS controller 1100, the NXS controller 1200 and the SPI
controllers 1300 and 1400 function in an analogous manner. As the
digital media device 700 is removed from its socket, pad 716 breaks
contact with the WP.backslash.-DT.backslash. port and the resistor
1102 pulls up the WP.backslash.-DT.backslash. port for a relatively
large number of clock cycles. This event is detected by the
microcontroller 1100. Next, the ground pad 715 makes contact with
the WP.backslash.-DT.backslash. port and pulls it down for a
relatively large number of clock cycles, an event which is also
sensed by the microcontroller 1100. The sequence of a prolonged
high and low drive of the WP.backslash.-DT.backslash. port is
interpreted by the microcontroller 1100 as a card removal
operation, and the microcontroller 1100 then begins the process of
powering down the interface circuits. During the power down
operation, pads 717 and 718 break contact with their respective
ports, which are protected since they contact only the
non-conductive material of the body of the digital media device
700. Power-down is completed before any pads of the digital media
device can come into improper contact with pads of the socket,
thereby prevent damage to any circuits of the host or the digital
media device.
[0071] It will be appreciated that pad 716 performs two functions,
the write protect function and the card detect function, thereby
eliminating the need for another contact pad.
[0072] Preferably, the digital media devices of the family 300 are
fabricated using surface mount techniques or "Chip on Board"
("COB") techniques. Digital media devices 310 and 320 of FIG. 3 and
the digital media device 1500 of FIG. 15 are illustrative of
surface mount techniques. COB techniques include a chip-on-board
modular technique, of which the digital media devices 330, 340 and
350 of FIG. 3 and the digital media devices 1600 and 1700 of FIGS.
16 and 17 are illustrative, and a chip-on-board direct technique,
of which the digital media device 360 of FIG. 3 and the digital
media device 1800 of FIG. 18 are illustrative. The COB techniques
are advantageous in that they are particularly inexpensive.
[0073] FIG. 15 shows in cross-section a digital media device 1500
having two packaged memory integrated circuits mounted using
surface mount techniques. It will be appreciated that only a single
packaged integrated circuit may be used if desired, or more than
two packaged integrated circuits may be used if space permits. A
contact pad array 1520, represented by contact pads 1522 and 1526,
is fabricated on the body 1510 using well known printed circuit
board techniques. The body 1510 is made of any suitable preferably
insulate material such as plastic, fiberglass, ceramic, PVC, PVCA,
FR4, or any suitable rigid or semi-rigid, nonconductive, and
durable material. Packaged integrated circuits 1540 and 1550, which
may be packaged in any convenient manner although low profile
plastic dual flat pack packaging is preferred, are mounted on
opposite sides of the body 1510. Alternatively, packaged integrated
circuits 1540 and 1550 may be mounted on the same side of the body
1510 if space allows. A suitable interconnect network is laid out
between the packaged integrated circuits 1540 and 1550 and the
contact pad array 1520 using well known printed circuit board
techniques. A suitable encasing material 1530 is placed about the
packaged integrated circuits 1540 and 1550 to provide protection
and a gripping surface for manual handling of the digital media
device 1500. The encasing material may encase the entire end of the
digital media device, as shown by the digital media device 310
(FIG. 3), or may be localized about the packaged integrated circuit
chips as shown in FIG. 15 and by the digital media device 320 (FIG.
3) so as to leave the long edges of the digital media device
uncovered so that the digital media device 320 may be inserted
fully into a slot via edge guides (not shown).
[0074] FIG. 16 shows in cross-section a digital media device 1600
having one die mounted using a COB modular technique. A cavity is
milled in the body 1610 for receiving an memory integrated circuit
die 1640. Alternatively, the body 1610 may be made of laminated
sheets, with the cavity being obtained by stamping out portions of
some of the sheets. The die 1640 is attached to a substrate 1620,
which is made of any suitable preferably insulative material such
as plastic, fiberglass, ceramic, PVC, PVCA, FR4, or any suitable
rigid or semi-rigid, nonconductive, and durable material.
Alternatively, a conductive material may be used provided
insulative structures are provided where necessary for proper
electrical operation. Wire bonds such as 1642 and 1644 electrically
connect bonding pads on the die 1640 to conductive material that
fills vias underlying the contact pads of the contact pad array
1621; contact pads 1622 and 1626 are illustrative. Suitable
electrically conductive material for the vias and techniques for
filling the vias are well known in the art. A mass of epoxy,
plastic or other suitable encapsulation material (not shown) is
placed over the die 1640 and the wire bonds, e.g. wire bonds 1642
and 1644, to protect these elements. The body 1610 is made of
similar material as the substrate 1620. Alternatively, a more
flexible material or a thinner sheet of rigid or semi-rigid
material may be used for the body 1610 if desired, provided the
substrate 1620, the encapsulation material (not shown), or both
provide sufficient rigidity so that the die 1640 and the wire
bonds, e.g. wire bonds 1642 and 1644, do not fail due to mechanical
stress during normal use.
[0075] FIG. 17 shows in cross-section a digital media device 1700
having two memory integrated circuit die 1740 and 1750 mounted
using COB techniques. Although dimensionally different, the
elements of the digital media device 1700 are similar to the
elements of the digital media device 1600. The die 1750 is
electrically connected to the contact pads of the contact pad array
1721 (contact pads 1722 and 1726 are illustrative) by a suitable
interconnect network laid out on the substrate 1720 between the
integrated circuits 1740 and 1750 and the contact pad array 1721
using well known printed circuit board techniques.
[0076] FIG. 18 shows in cross-section a digital media device 1800
having two die mounted using a COB direct technique. The COB direct
technique is similar to the COB modular technique, but the chips
1840 and 1850 are mounted on the surface of the body 1810 rather
than mounted on a PCB which is then inserted into a cavity of the
body. The chips 1840 and 1850 are electrically connected to an
interconnect pattern (not shown) on the body 1810 of the digital
media device 1800 using any suitable technique such as wire
bonding, and the chips 1840 and 1850 are encapsulated in any
suitable protective material 1830 such as epoxy. Advantageously,
the COB technique results in nearly planar major surfaces due to
the thinness of the chips 1840 and 1850; compare the digital media
devices 300 of FIG. 3 and 1500 of FIG. 15 with the digital media
devices 360 of FIG. 3 and 1800 of FIG. 18.
[0077] A digital media device incorporates multiple chips or
integrated circuits ("IC") to achieve greater memory capacity. When
two or more chips or integrated circuits compliant with the NXS
protocol as described in the aforementioned Challa et al. patent
are used, they preferably share common power, ground clock, and
data I/O buses. Static address terminals on the chips or integrated
circuits are tied to or supplied with V.sub.CC or ground as
appropriate to impart an address to them so that one of them can be
selected in accordance with an address furnished over the data I/O
bus. In contrast, the SPI protocol uses separate chip select
ports.
[0078] The digital media devices of the family 300 have numerous
applications due to their various advantageous properties, which
include the ability to be inserted and removed frequently, easily,
and in a fool-proof manner, a small and convenient size and form
factor, a high memory capacity, non-volatile storage, low power
consumption, low voltage operation, and general durability. For
example, the digital media devices of the family 300 is useful in
communications, consumer, office, desktop publishing, portable
computing, and industrial applications.
[0079] In communications, the digital media devices of the family
300 are useful with personal alpha-numeric pagers, two-way pagers,
and voice pagers (FIG. 19) for providing enhanced storage capacity.
The digital media devices of the family 300 are useful with two way
radios, cellular telephones (FIG. 20), and land line telephones for
maintaining user-specific information such as large telephone
directories, telephone logs, outgoing and incoming voice messages
for personal answering machines, and outgoing and incoming data
storage for facsimile, electronic mail, and transferred files. The
digital media devices of the family 300 are useful with modems for
storing all of the various forms of data within the capability of
the modem. For example, a fax/data/phonemail modem furnished with
the capability to receive and store e-mail, transferred files,
facsimile messages, and digitized voice data stores this data on
the digital media device, which is then removed from the modem and
plugged into a personal computer or personal data assistant for
retrieval or play-back. Conversely, data is downloaded from the
personal computer or personal data assistant to the digital media
device, which is then removed from the personal computer or
personal data assistant and plugged into a modem for
transmission.
[0080] In consumer applications, office applications, and desktop
publishing, the digital media devices of the family 300 are useful
with digital cameras (FIG. 21) for storing pictures and voice
recording (e.g. annotations), which are retrievable immediately or
later by the camera or a personal computer or other digital media
access device, or which may be transferred by modem or digitally to
such devices. In addition, the digital media devices of the family
300 are useful with image scanners, digital voice recorders,
pen-based tablets, and video capture devices.
[0081] In portable computing, the digital media devices of the
family 300 are useful with image scanners, and especially handheld
image scanners (FIG. 22), for acquiring digital images for later
retrieval by a personal computer or other digital media access
device, or which may be transferred by modem or digitally to such
devices. The digital media devices of the family 300 are useful
with computers, especially personal data assistants and laptop
personal computers, and even personal data assistants and laptop
computers having PC card slots and serial ports through the use of
suitable adapters (FIG. 23), for providing significant additional
data storage at a lower initial cost, since memory need be
purchased only as required and remains useful even as more memory
is acquired. Presently, sufficient data storage must be purchased
to anticipate future needs, or replaced with higher capacity memory
at a later date.
[0082] Digital media devices are also useful for temporary storage
of downloadable code in a low cost computer system such as an
internet terminal, where the downlodable code is selectively copied
into RAM for execution.
[0083] The digital media devices of the family 300 are particularly
useful in certain industrial applications such as environmental
monitors, industrial process monitors, medical monitors, and
computer controlled machinery. For example, when used as a
removable storage media for computer controlled machinery, the
digital media device stores controlling and profiling data
downloaded from a computer and provides access to this information
when plugged into the computer-controlled machinery. When used as a
removable storage media of a medical data recorder or monitor, the
digital media device stores the medical history of a patient, the
doctor's instructions to the medical staff, and medication
requirements, including amounts, times, special administration
procedures, EKG patterns, blood pressure, and other monitored data.
In use, the medical digital media card preferably is attached to
the patient's clip-board. During a visit, the doctor plugs the
medical media device card into a voice recorder and dictates oral
instructions, then returns the medical media device card to the
patient's clip-board. To administer medication, the nurse plugs the
medical media device card into a medication administration and
monitoring machine, which plays back any special instructions given
by the doctor and records the dose and time of medication, and
returns the medical media device card to the patient's clip-board.
Any special observations may be dictated for future play-back by
the doctor. Other industrial applications include hand held
terminals, electronic meters, portable bar code readers, global
positioning terminals, talking sales displays, signal generators
and analyzers, flight recorders, and environmental data
loggers.
[0084] Advantageously, due to its removable nature, the digital
media devices of the family 300 provide a common storage media
among many different electronic products, as well as a linking
media among these products. For example, the same digital media
device is suitable for storing pictures taken with a digital
camera, recording messages from a cellular phone, recording a
shopping list from a voice recorder, store an e-mail message
received with a modem, store text and graphics scanned from a book,
and store stock quotes downloaded from a commercial service. All of
this data is available to any electronic product capable of
utilizing it. Moreover, the same digital media device also may
store applications programs for using the data, so that the host
device need not have the application program permanently installed
to use the stored data.
[0085] To maintain low cost, preferable the logic for reading,
programming, and controlling the memory on-board the digital media
devices of the family 300 is implemented in the host or in an
adapter, although some inexpensive additional functionality such as
error correction may be provided on-board the digital media device
itself if desired. Suitable logic for reading, programming, and
controlling the memory on-board the digital media device is
described in the aforementioned Challa patent. Examples of
arrangements in which the logic is located in the host are the
voice/data pager of FIG. 19, the cellular telephone of FIG. 20, the
digital camera of FIG. 21, and the image scanner of FIG. 22. An
example of an arrangement in which the logic is located in an
adapter is the laptop computer and PCMCIA flash memory card of FIG.
23. The laptop computer 2310 is any laptop computer having a PCMCIA
slot. The adapter 2320 is any ATA PC card containing suitable logic
and a socket for receiving a digital media device 2330, and
preferably an ATA PC card using the technology described in the
aforementioned Challa et al. patent. Such cards are available in
various memory capacities from Nexcom Technology, Inc. of
Sunnyvale, Calif., under the trademark NexFLASH. Other examples of
suitable adapters include serial and parallel port interface
adapters and compact flash cards such as 110 containing a socket
for receiving the digital media device. It will be appreciated that
adapters may have two or more sockets to provide increased memory
capacity.
[0086] An adapter 2400 suitable for inexpensively interfacing a
standard PC port such as a parallel port to a digital media device
such as, for example, an SPI protocol device such as that shown in
FIG. 14 is shown in the schematic diagram of FIG. 24. The adapter
2400 essentially maps the pins of the standard parallel port to the
pads of either an NXS or SPI protocol digital media device, and
contains no microcontroller and no or minimal logic. Instead,
digital media device memory access functions such as DOS file
system compatibility, buffering, multiple chip access, data
validation, and API are implemented in software running on the
host.
[0087] As shown in FIG. 24, pin 8 of P1 is assigned to signal
5/3_SEL, which provides dual voltage control (5.0V and 3.3V) via
the bit 6 of the parallel port. Pin 7 of P1 is assigned to signal
SHUTDOWN, which provides power control via the setting bit 5 on the
parallel port. Pin 4 of P1 is assigned to signal CS0, which is a
chip select signal common to both GSM or DIP flash memory package
types at location device 0. Pin 9 of P1 is assigned to signal CS1,
which is another chip select signal for GSM to accommodate a
digital media device containing two integrated circuits. A jumper
JP1 selects CS1 to TSOP or DIP flash memory package type at the
location of device 1. A jumper JP2 selects either low voltage AC or
low voltage DC input. A voltage regulator U5 is included. A jumper
JP3 selects VDD from either UNREG, which is an external power
source, or REG, which is an internal DC voltage regulator. Pin 10
of P1 is assigned to signal W_DET for device detection.
[0088] The adapter 2400 includes various chip sockets U1, U2 and U3
for additional flexibility, and is particularly suitable for use as
a development kit. However, the chip sockets U1, U2 and U3 may be
omitted and the adapter 2400 packaged with or without the regulator
U5 for consumer use, as shown by the adapter 2340 of FIG. 23, which
is shown plugged into the parallel port of the laptop computer 2310
and receiving digital media device 2350. It will be appreciated
that a "mapping" type adapter may also be packaged in a PC card
shell that plugs into the PCMCIA port of the laptop 2310 and
receives one or more digital media devices, provided appropriate
software is installed on the laptop computer 2310 for controlling
access to the digital media device(s).
[0089] The description of the invention set forth herein is
illustrative, and is not to be taken as a limitation on the scope
of the invention. Variations and modifications of the embodiments
disclosed herein are possible. For example, although several
examples of form factors and various dimensions are given, these
examples and dimensions are illustrative. Moreover, specific
embodiments contain eight and six pins, but fewer or more pins may
be used if desired, as well as an odd number of pins. Moreover,
some pins may be assigned different functions than specified by the
NXS and SPI protocols, including test functions. These and other
variations and modifications of the embodiments disclosed herein
may be made without departing from the scope and spirit of the
invention as set forth in the following claims.
* * * * *