U.S. patent application number 12/208847 was filed with the patent office on 2009-01-15 for semiconductor device.
Invention is credited to Ryo Fukuda, Tomohisa TAKAI.
Application Number | 20090015310 12/208847 |
Document ID | / |
Family ID | 35944899 |
Filed Date | 2009-01-15 |
United States Patent
Application |
20090015310 |
Kind Code |
A1 |
TAKAI; Tomohisa ; et
al. |
January 15, 2009 |
SEMICONDUCTOR DEVICE
Abstract
A semiconductor device transfers first data to a circuit block.
The semiconductor device is provided with a storage circuit
configured to store the first data, a shift register configured to
set the first data, a transfer circuit configured to transfer the
first data from the shift register to the circuit block, a first
input terminal configured to receive a first signal indicating the
end of a transfer operation, a resetting signal-generating circuit
configured to generate a resetting signal for resetting the shift
register based on the first signal, a setting signal-generating
circuit configured to generate a setting signal for setting the
first data in the shift register again after the shift register is
reset, and an output circuit configured to externally output the
first data that has been set again.
Inventors: |
TAKAI; Tomohisa;
(Kawasaki-shi, JP) ; Fukuda; Ryo; (Yokohama-shi,
JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Family ID: |
35944899 |
Appl. No.: |
12/208847 |
Filed: |
September 11, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11066250 |
Feb 28, 2005 |
7433978 |
|
|
12208847 |
|
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Current U.S.
Class: |
327/291 |
Current CPC
Class: |
G11C 16/20 20130101;
G11C 29/802 20130101; G11C 29/028 20130101; G11C 2029/4402
20130101; G11C 7/20 20130101 |
Class at
Publication: |
327/291 |
International
Class: |
H03K 3/00 20060101
H03K003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 2, 2004 |
JP |
2004-255830 |
Claims
1. A semiconductor device comprising: an output circuit configured
to output a first signal; a transmission circuit including a
plurality of circuit sections connected in series, each of the
circuit sections including a load capacitance element that operates
based on the first signal, and a buffer circuit serving to supply
the first signal to subsequent ones of the circuit sections; and a
generation circuit configured to generate a pulse signal by
inverting the polarity of the first signal after the first signal
is transmitted to the circuit sections.
2. The semiconductor device according to claim 1, wherein the
generation circuit inverts the polarity of the first signal upon
receipt of a second signal, obtained when the first signal is
output from the circuit section of a last stage.
3. The semiconductor device according to claim 1, wherein the
buffer circuit includes two inverter circuits connected in series.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of and claims the benefit of
priority under 35 U.S.C. .sctn.120 from U.S. Ser. No. 11/066,250
filed Feb. 28, 2005, and claims the benefit of priority under 35
U.S.C. .sctn.119 from Japanese Patent Application No. 2004-255830
filed Sep. 2, 2004, the entire contents of each of which are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a semiconductor device,
more particularly to a semiconductor integrated circuit comprising
a circuit block which operates based on initializing data and a
circuit which transfers the initializing data.
[0004] 2. Description of the Related Art
[0005] The amount of analog data output from a circuit made up of
transistors inevitably varies depending upon the characteristic
variation among the transistors. The variation amount of analog
data can be corrected to be a predetermined value, and this
correction operation is known as "trimming." Redundancy is also
known in the art as a technology for remedying defective cells of a
memory by use of a redundancy circuit.
[0006] To put the trimming or redundancy to practical use, a data
distribution circuit is provided to send trimming data based on
which the trimming is performed, or redundancy data based on which
the redundancy is performed. The data distribution circuit
comprises programmable nonvolatile elements for retaining
initializing data such as trimming data or redundancy data. It also
comprises a shift register made up of flip-flops and configured to
store the initializing data. The shift register is made up of
flip-flops which are equal in number to the pieces of the
initializing data. The data distribution circuit sends the
initializing data to a group of circuit blocks located far away.
Each circuit block performs trimming and redundancy, using the
initializing data it receives.
[0007] The above configuration is disadvantageous in the following
points: (i) it is not possible to externally confirm whether the
initializing data of the nonvolatile elements are correctly set in
the shift register, and (ii) it is not possible to externally
confirm whether the initializing data are correctly supplied to the
circuit blocks. Furthermore, the nonvolatile elements are
programmable only once. After the nonvolatile element is
programmed, the data used for programming is the only data that is
available, and the circuit blocks cannot use data other than the
programming data.
[0008] When the data of the nonvolatile elements is set in the
shift register, the above configuration uses pulse signals. The
shift register is made up of a plurality of flip-flops. Where the
initializing data have a large data width, the number of flip-flops
required is large. Therefore, a plurality of shift registers, each
corresponding to a predetermined number of bits, are used, and
these shift registers are connected in series to deal with the
initializing data. To transmit pulse signals to the multi-stage
shift register, a plurality of buffers made up of transistors are
used.
[0009] Where a plurality of buffers are used for data setting, the
characteristic difference among the transistors becomes more marked
in accordance with an increase in the number of pieces of data, and
the pulse signals may not be transmitted to the final stage with a
satisfactory margin. In other words, the characteristic difference
among the transistors gives rise to a decrease in the pulse width
of the pulse signals. In the worst case, the pulse signals may be
lost during the transmission. Owing to this, data may not be set in
the shift register of the final stage.
[0010] A semiconductor device related to the above art enables
external setting of trimming data. Such a semiconductor device is
disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2003-110029,
for example.
BRIEF SUMMARY OF THE INVENTION
[0011] A semiconductor device according to the first aspect of the
present invention transfers first data to a circuit block and
comprises: a storage circuit configured to store the first data; a
shift register configured to set the first data; a transfer circuit
configured to transfer the first data from the shift register to
the circuit block; a first input terminal configured to receive a
first signal indicating the end of a transfer operation; a
resetting signal-generating circuit configured to generate a
resetting signal for resetting the shift register based on the
first signal; a setting signal-generating circuit configured to
generate a setting signal for setting the first data in the shift
register again after the shift register is reset; and an output
circuit configured to externally output the first data that has
been set again.
[0012] A semiconductor device according to the second aspect of the
present invention comprises: an output circuit configured to output
a first signal; a transmission circuit including a plurality of
circuit sections connected in series, each of the circuit sections
including a load capacitance element that operates based on the
first signal, and a buffer circuit serving to supply the first
signal to subsequent ones of the circuit sections; and a generation
circuit configured to generate a pulse signal by inverting the
polarity of the first signal after the first signal is transmitted
to the circuit sections.
[0013] A semiconductor device according to the third aspect of the
present invention comprises: a storage circuit configured to store
first data; a shift register configured to set or reset the first
data; a first resetting signal-generating circuit configured to
generate a resetting signal for resetting the shift register; and a
second resetting signal-generating circuit configured to generate a
first detection signal indicating that the shift register has been
reset after the resetting signal is transferred to the shift
register, the first resetting signal-generating circuit disabling
the resetting signal based on the first detection signal.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0014] FIG. 1 is a schematic diagram illustrating a semiconductor
integrated circuit 1 according to the first embodiment of the
present invention.
[0015] FIG. 2 is a block diagram showing the configurations of the
shift register 5 and storage circuit 6 depicted in FIG. 1.
[0016] FIG. 3 is a block diagram showing an example of the
configuration of the semiconductor integrated circuit 1 depicted in
FIG. 1.
[0017] FIG. 4 is a block diagram showing the configuration of the
control section 4 depicted in FIG. 3.
[0018] FIG. 5 is a circuit block diagram showing the configuration
of the flip-flop section 7 depicted in FIG. 3.
[0019] FIG. 6 is a circuit diagram showing the configuration of the
flip-flop circuit 8 depicted in FIG. 5.
[0020] FIG. 7 is a timing chart illustrating an operation of the
flip-flop circuit 8.
[0021] FIG. 8 is a timing chart illustrating an operation of the
data distribution apparatus 2.
[0022] FIG. 9 is a schematic diagram illustrating a semiconductor
integrated circuit 10 according to the second embodiment of the
present invention.
[0023] FIG. 10 is a circuit diagram showing the configuration of
the transmission circuit 12 depicted in FIG. 9.
[0024] FIG. 11 is a block diagram showing the configuration of the
control section 11 depicted in FIG. 9.
[0025] FIG. 12 is a timing chart illustrating an operation of the
semiconductor integrated circuit 10.
[0026] FIG. 13 is a schematic diagram illustrating a semiconductor
integrated circuit 20 according to the third embodiment of the
present invention.
[0027] FIG. 14 is a block diagram showing the configuration of the
first control section 21 depicted in FIG. 13.
[0028] FIG. 15 is a block diagram showing the configuration of the
second control section 22 depicted in FIG. 13.
[0029] FIG. 16 is a circuit diagram showing a specific
configuration of the first control section 21 depicted in FIG.
14.
[0030] FIG. 17 is a circuit diagram showing a specific
configuration of the second control section 22 depicted in FIG.
15.
[0031] FIG. 18 is a timing chart illustrating an operation of the
semiconductor circuit 20.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Embodiments of the present invention will now be described
with reference to the accompanying drawings. In the descriptions
below, structural elements that are similar or correspond to each
other will be denoted by the same reference numerals, and a
repeated description will be given only where necessary.
First Embodiment
[0033] FIG. 1 is a schematic diagram illustrating a semiconductor
integrated circuit 1 according to the first embodiment of the
present invention. The semiconductor integrated circuit 1 comprises
a data distribution apparatus 2 and a group of circuit blocks 3
(which will be collectively referred to as "circuit block group 3"
hereinafter).
[0034] The data distribution apparatus 2 has a clock terminal T2.
Clock signal CLK is externally supplied to the clock terminal T2.
The data distribution apparatus 2 operates in synchronism with the
clock signal CLK.
[0035] The data distribution apparatus 2 transfers initializing
data to the circuit block group 3. The data distribution apparatus
2 includes a control section 4, a shift register 5 and a storage
circuit 6.
[0036] The storage circuit 6 stores the initializing data. The
storage circuit 6 can be programmed only once to store the
initializing data. The storage circuit 6 is made up of a plurality
of nonvolatile elements (ROM: read only memories), the number of
which corresponds to the number of bits of the initializing
data.
[0037] The shift register 5 sets the initializing data in itself.
Specifically, the shift register 5 fetches and holds the
initializing data. On the basis of the clock signal CLK, the shift
register 5 shifts the initializing data. Then, the shift register 5
sends the initializing data to the circuit block group 3.
[0038] FIG. 2 is a block diagram showing the configurations of the
shift register 5 and storage circuit 6 depicted in FIG. 1. The
storage circuit 6 includes a plurality of nonvolatile elements
ROM1-ROMm, the number of which corresponds to the number of bits of
the initialing data. The shift register 5 includes a plurality of
flip-flops FF1-FFm. These flip-flops are arranged in correspondence
to the nonvolatile elements.
[0039] The data stored in the nonvolatile elements are set in the
flop-flops FF. The flip-flop FF outputs the set data in synchronism
with the clock signal CLK. Furthermore, The flip-flop FF outputs
data input from the flip-flop FF adjacent to the input side in
synchronism with the clock signal CLK. In this manner, the shift
register 5 outputs all data stored in the storage circuit 6.
Externally-supplied input data may be set in the flip-flops FF of
the shift register 5. After being retained for a predetermined
time, the input data is output from the shift register 5.
[0040] The control section 4 controls the operation of setting the
initializing data in the shift register 5. The control section 4
also controls the operation of transferring the initializing data
from the shift register 5 to the circuit block group 3.
[0041] The circuit block group 3 is initialized based on the
initializing data. The circuit block group 3 includes a reference
voltage generating circuit, for example. The reference voltage
generating circuit performs a trimming operation on the basis of
the initializing data. In other words, the reference voltage
generating circuit corrects an output voltage to a predetermined
value on the basis of the initializing data (which is trimming data
in the example).
[0042] The circuit block group 3 may include a semiconductor
storage device. The semiconductor storage device has a redundancy
circuit and performs a redundancy on the basis of the initializing
data. In other words, the semiconductor storage device remedies a
defective cell of the memory by use of the redundancy circuit.
[0043] The data distribution apparatus 2 has input terminal T3
which enables access to the shift register 5, and output terminal
T1 from which data is output. External input data EDI is supplied
to input terminal T3. External output data EDO is supplied from
output terminal T1.
[0044] A description will now be given as to how the semiconductor
integrated circuit 1 operates. First of all, the control section 4
sets the data of the storage circuit 6 in the shift register 5.
Then, the control section 4 transfers the set data from the shift
register 5 to the circuit block group 3. Subsequently, the control
circuit 4 resets the shift register 5.
[0045] The control circuit 4 sets data in the shift register 5 once
again. Upon receipt of clock signal CLK externally supplied
thereto, the data is externally output from output terminal T1.
[0046] In synchronism with clock signal CLK supplied from input
terminal T2, the shift register 5 is supplied with external input
data EDI from the input terminal T3. The control circuit 4 sends
this data to the circuit block group 3.
[0047] The circuit configuration and circuit operation of the
semiconductor integrated circuit 1 shown in FIG. 1 will be
described in more detail, referring to the drawings. FIG. 3 is a
block diagram showing an example of the configuration of the
semiconductor integrated circuit 1 depicted in FIG. 1.
[0048] The data distribution apparatus 2 and the circuit block
group 3 are connected to each other through an input/output signal
line 9. The data distribution apparatus 2 has output terminals T1
and T6 and input terminals T2, T3, T4 and T5. Input terminal T2
receives clock signal CLK externally supplied thereto. Input
terminal T3 receives external input data EDI externally supplied
thereto. Input terminal T3 also receives commands externally
supplied thereto.
[0049] Input terminal T4 receives a transfer start signal FXOK
externally supplied thereto. The transfer start signal FXOK
designates the start of the operation of transferring the
initializing data. The transfer start signal FXOK is supplied from
the control block group 3, from a control circuit controlling this
control block group 3, or from another circuit.
[0050] Input terminal T5 receives a transfer end signal FXDONE
externally supplied thereto. The transfer end signal FXDONE
designates the end of the operation of transferring the
initializing data. Like the transfer start signal FXOK, the
transfer end signal FXDONE is supplied from the control block group
3, from the control circuit controlling the control block group 3,
or from another circuit. The signals received at these terminals
are supplied to the control section 4 through the terminals of the
control section 4.
[0051] Output terminal T1 outputs an external output data EDO
provided by the control section 4. Output terminal T6 outputs
output data DO provided by the control section 4. The output data
DO is supplied to the circuit block group 3 through the
input/output signal line 9.
[0052] FIG. 4 is a block diagram showing the configuration of the
control section 4 depicted in FIG. 3. The control section 4
comprises an output circuit 4a, a resetting signal-generating
circuit 4b, a setting signal-generating circuit 4c, a transfer
circuit 4d, an input circuit 4e and a command decode circuit
4f.
[0053] The output circuit 4a outputs data which is set in the shift
register 5 again. The resetting signal-generating circuit 4b
generates a resetting signal FCLRS used for resetting the shift
register 5 or for releasing it from the reset state. To be more
specific, the resetting signal-generating circuit 4b generates a
signal FCLRS used for reset-releasing, upon reception of signal
FXOK, and generates the signal FCLRS used for resetting, upon
reception of signal FXDONE.
[0054] The setting signal-generating circuit 4c generates a setting
signal FSETS used for setting data in the shift register 5. To be
more specific, the setting signal-generating circuit 4c generates
the setting signal FSETS after the shift register 5 is released
from the reset state. The transfer circuit 4d transfers data from
the shift register 5 to the circuit block group 3.
[0055] The input circuit 4e receives external input data EDI, which
is externally supplied thereto. The input circuit 4e supplies the
external input data EDI to the shift register 5. The command decode
circuit 4f interprets the command supplied to the input terminal
T3. Based on the command, the command decode circuit 4f controls
the circuits of the control section 4. The clock signal CLK input
to the control section 4 is supplied to the circuits provided in
the control section 4. The clock signal CLK is supplied from the
control section 4 to the shift register 5.
[0056] The data distribution circuit 2 comprises a plurality of
flip-flop sections 7. FIG. 5 is a circuit block diagram showing the
configuration of each flip-flop section 7. Each flip-flop section 7
is made up of, for example, five flip-flop circuits 8 connected in
series. Each flip-flop circuit 8 includes one nonvolatile element
and one flip-flop FF.
[0057] Resetting signal FCLRIN, setting signal FSETIN and clock
signal CLKIN are supplied to the flop-flop section 7. Signal FCLRIN
is supplied to buffer BF1. This buffer BF1 includes two inverter
circuits IV1 and IV2 connected in series. The buffer BF1 outputs
resetting signal FCLR. This signal, FCLR, is supplied to the five
flip-flop circuits 8 of the flip-flop section 7, and also to the
flip-flop section 7 of the next stage.
[0058] Signal FSETIN is supplied to buffer BF2. This buffer BF2
includes two inverter circuits IV3 and IV4 connected in series. The
buffer BF2 outputs setting signal FSET. This signal, FSET, is
supplied to the flip-flop circuits 8 of the flip-flop section 7,
and also to the flip-flop section 7 of the next stage.
[0059] Signal CLKIN is supplied to buffer BF3. This buffer BF3
includes two inverter circuits IV5 and IV6 connected in series.
Inverter circuit IV5 inverts clock signal CLKIN, thereby producing
clock signal CLKB. This clock signal, CLKB, is supplied to the
flip-flop circuits 8 of the flip-flop section 7. Buffer BF3 outputs
clock signal CLK. This clock signal, CLK, is supplied to the
flip-flop circuits 8 of the flip-flop section 7, and also to the
flip-flop section 7 of the next stage.
[0060] Input data IN is supplied to the flip-flop section 7. In
synchronism with the clock signal CLK, the input data IN is
shifted, and is produced as output data OUT by the flip-flop
section 7.
[0061] FIG. 6 is a circuit diagram showing the configuration of the
flip-flop circuit 8. The flip-flop circuit 8 comprises clocked
inverter circuits 8a and 8c, inverter circuits 8b, 8e and 8f, a
transfer gate 8d, N-type MOS transistors 8h, 8k and 8l, P-type MOS
transistors 8g, 8i and 8j, and a nonvolatile element ROM. The
nonvolatile element is a fuse element, for example.
[0062] When clock signal CLK is "0", clocked inverter circuit 8a
outputs data obtained by inverting input data INX. When clock
signal CLK is "1", clocked inverter circuit 8c outputs data which
is obtained by inverting the input data thereto. Inverter circuit
8b and clocked inverter circuit 8c constitute a holding circuit.
This holding circuit holds the data output from clocked inverter
circuit 8a when clock signal CLK is "1."
[0063] Transfer gate 8d is made of an N-type MOS transistor and a
P-type MOS transistor that are connected in parallel to each other.
When clock signal CLK is "1", transfer gate 8d allows outputting
data. The output terminal of the transfer gate 8d is connected to
node FNODE. This node is connected to the input terminal of
inverter circuit 8e.
[0064] Transistors 8i to 8l jointly constitute a clocked inverter
circuit. This clocked inverter circuit and inverter circuit 8e
constitute a holding circuit. When clock signal CLK is "0", the
holding circuit holds the data appearing at node FNODE.
[0065] FIG. 7 is a timing chart illustrating an operation of the
flip-flop circuit 8. When signal FCLR is "0" and signal FSET is
"0", transistor 8g is turned on and transistor 8h is turned off. In
this case, the potential at node FNODE is Vdd (i.e., data "1").
Accordingly, the flip-flop circuit 8 is reset.
[0066] When signal FCLR is "1" and signal FSET is "1", transistor
8g is turned off and transistor 8h is turned on. In this case, the
potential at node FNODE is the same as the data stored in the
nonvolatile element. In other words, where the fuse element is cut
off, the data appearing at node FNODE is data "1." Where the fuse
element is not cut off, the data appearing at node FNODE is data
"0." In this manner, the flip-flop circuit 8 stores the data held
in the nonvolatile element.
[0067] In synchronism with clock signal, the flip-flop circuit 8
outputs the data held at node FNODE, and the input data supplied to
the flip-flop circuit 8 is held at node FNODE. In this manner, the
shift register 5 outputs the data stored in each nonvolatile
element.
[0068] A description will now be given of how the semiconductor
integrated circuit 1 of the above configuration operates. FIG. 8 is
a timing chart illustrating an operation of the data distribution
apparatus 2.
[0069] The data distribution apparatus 2 is supplied with transfer
start signal FXOK. Upon receipt of transfer start signal FXOK, the
data distribution circuit starts a transfer operation. To be more
specific, when signal FXOK changes from "0" to "1", the control
section 4 changes resetting signal FCLRS from "0" to "1." As a
result, all flip-flops FF are released from the reset state. It
should be noted here that flip-flops FF are reset when resetting
signal FCLRS is "0" and released from the reset state when
resetting signal FCLRS is "1."
[0070] After all flip-flops FF are released from the reset state,
the control section 4 outputs setting signal FSETS, which is a
pulse signal of data "1." This pulse signal is supplied to the
flip-flop circuit 8. Upon receipt of it, the flip-flop circuit 8
stores data held in the nonvolatile element. When clock signal CLK
is supplied thereafter, the control section 4 transfers data from
the shift register 5 to the circuit block group 3.
[0071] After the data is transferred to the circuit block group 3,
transfer end signal FXDONE is input. To be more specific, signal
FXDONE changes from "0" to "1", the control section outputs signal
FCLRS, which is a pulse signal of data "0." This pulse signal is
supplied to each flip-flop circuit 8. As a result, all flip-flop
circuits 8 are reset.
[0072] When signal FCLRS changes from "0" to "1", all flip-flops FF
are released from the reset state. In response to this, the control
section 4 outputs signal FSETS, which is a pulse signal of data
"1." This pulse signal is supplied to each flip-flop circuit 8. As
a result, each flip-flop circuit 8 stores the data held in the
nonvolatile element one more time. When clock signal CLK is
externally supplied, the control section 4 outputs external output
data EDO from output terminal T1.
[0073] A description will now be given as to how external input
data EDI is transferred from the data distribution apparatus 2 to
the circuit block group 3.
[0074] When external input data EDI is input, the control section 4
produces output data DOX corresponding to data EDI and supplies it
to the shift register 5. Thereafter, when clock signal CLK is
input, the shift register 5 stores output data DOX. When clock
signal CLK is input, the control section 4 transfers the data from
the shift register 5 to the circuit block group 3.
[0075] The operation of the data distribution apparatus 2 is
controlled by supplying commands to it. For example, the control
section 4 may be so configured as not to perform a data transfer
operation despite the receipt of transfer start signal FXOK.
Alternatively, the control section may be so configured as to
transfer only the data stored in some of the nonvolatile elements.
Furthermore, after the data transfer operation, the control section
4 may reset the nonvolatile elements without storing data in them.
Still further, the control section 4 may be so designed as to write
"0" in all flip-flops FF, or to write "0" and "1" alternately in
flip-flops FF.
[0076] As detailed above, in the present embodiment, the data
stored in the nonvolatile elements are output from the data
distribution apparatus 2, and externally input data are transferred
to the circuit block group 3.
[0077] The present embodiment enables the nonvolatile elements and
the shift register to be accessed externally. This leads to
improvement of the performance of semiconductor integrated circuits
1 and the improvement of the manufacturing yield.
[0078] The data stored in the nonvolatile elements can be
externally read out. The readout data may be compared with the data
that is used for programming the semiconductor integrated circuit 1
at the time of manufacture, and the results of this comparison can
be used for evaluating the nonvolatile elements and the shift
register.
[0079] The externally input data may be transferred to the circuit
block group 3. This transfer operation is useful to the case where
the data in the nonvolatile elements are used for redundancy or
trimming. This is because there may be a case where the data in the
nonvolatile elements need to be rewritten inside the chip after
they are used for programming.
Second Embodiment
[0080] FIG. 9 is a schematic diagram illustrating a semiconductor
integrated circuit 10 according to the second embodiment of the
present invention. The semiconductor integrated circuit 10
comprises a control section 11 and a transmission circuit 12.
[0081] FIG. 10 is a circuit diagram showing the configuration of
the transmission circuit 12 depicted in FIG. 9. The transmission
circuit 12 comprises a plurality of circuits 13 connected in
series. The transmission circuit 12 receives input signal IN1
supplied from the control section 11, and produces output signal
OUT1. The input signal IN1 is sequentially transmitted to the
circuits 13 of the transmission circuit 12.
[0082] Each circuit 13 includes a buffer BF and a load capacitance
element LC. The buffer BF is made of two inverter circuits, such as
a P-type MOS transistor and an N-type MOS transistor. The load
capacitance element LC is, specifically, a parasitic capacitance
produced in the wiring line of the circuit 13, a gate capacitance
produced in the gate electrodes of the transistors of the circuit
13, a junction capacitance produced in the buffer BF, etc.
[0083] Input signal IN1 is supplied to the buffer BF. Using the
input signal IN1, the buffer BF drives the load capacitance element
LC. The buffer BF sends the input signal it receives to the
subsequent circuit 13 (i.e., to the buffer BF of the subsequent
circuit 13).
[0084] The circuit 13 may be any type of circuit as long as it
includes a buffer BF supplied with input signal IN1 and operates
based on input signal IN1.
[0085] FIG. 11 is a block diagram showing the configuration of the
control section 11. The control section 11 comprises an output
circuit 11a and a pulse generating circuit 11b. The output circuit
11a receives signal IN2 and outputs the same signal as signal OUT2.
Based on signal IN3 supplied from the transmission circuit 12, the
pulse generating circuit 11b inverts the polarity of signal IN2. As
can be seen from this, the control section produces pulse signals
on the basis of signals IN2 and IN3.
[0086] A description will now be given of an operation of the
semiconductor integrated circuit of the above configuration. FIG.
12 is a timing chart illustrating the operation of the
semiconductor integrated circuit 10. First of all, signal IN2
indicating the start of pulse transmission is supplied to the
control section 11. The polarity of signal IN2 is predetermined. In
response to signal IN2, the control section 11 outputs signal OUT2.
Signal OUT2 is supplied to the transmission circuit 12 as signal
IN1. After rising (falling), signal IN1 is transmitted through the
circuits 13 of the transmission circuit 12. When signal IN1 is
transmitted to the circuit 13 of the last stage, the transmission
circuit 12 produces signal OUT1.
[0087] The control section 11 receives the signal OUT1 produced
from the transmission circuit 12. The signal OUT1 is received as
signal IN3. Upon receipt of this signal, the control section lowers
the level of signal OUT2 (raises the level of signal OUT2). After
this, signal OUT1 falls (rises).
[0088] As detailed above, the present embodiment is featured in
that signal IN1 rises in response to the rise of signal IN2, which
indicates the start of transmission. Using signal OUT1 output from
the transmission circuit 12, signal IN1 is lowered in level.
[0089] The present embodiment is advantageous in that pulse signals
for driving the circuits 13 (load capacitance elements) can be
transmitted to the circuits 13 without fail. Hence, all load
capacitance elements LC can be reliably driven.
[0090] To enable the pulse signals to have a sufficient margin, a
delay element may be used. The use of the delay element provides a
long time between the reception of signal IN3 and the falling
(rising) of signal OUT2. This configuration is effective in
providing a pulse width corresponding to the length of time delayed
by the delay element. It is therefore possible to properly
determine the pulse width in accordance with the number of circuits
13 incorporated in the transmission circuit.
Third Embodiment
[0091] The third embodiment is obtained by applying the
transmission system described in relation to the second embodiment
to the first embodiment.
[0092] FIG. 13 is a schematic diagram illustrating a semiconductor
integrated circuit 20 according to the third embodiment of the
present invention. A semiconductor integrated circuit 20 comprises
a first control section 21, a second control section 22, a shift
register 5 and a storage circuit 6. The first and second control
sections 21 and 22 are connected to each other by means of signal
line STPSET and signal line STPCLR.
[0093] Illustration of a circuit block group 3 to which data is
supplied is omitted. Each of the first and second control sections
21 and 22 is provided with an output circuit 4a, a transfer circuit
4d, an input circuit 4e and a command decode circuit 4f (none of
which is shown).
[0094] The first control section 21 receives transfer start signal
FXOK and transfer end signal FXDONE. The first control section 21
supplies signal FCLR1 to the shift register 5. The shift register 5
receives the signal FCLR1 as signal FCLRIN. The first control
section 21 supplies signal SSOUT to the second control section 22.
The second control section 22 receives signal SSOUT as signal
SSIN.
[0095] The second control section 22 supplies signal FSET2 to the
shift register 5. The shift register 5 receives signal FSET2 as
FSETIN. The second control section 22 supplies signal SCOUT to the
first control section 21. The first control section 21 receives
signal SCOUT as signal SCIN.
[0096] Signal FSETIN is transmitted sequentially to the flip-flop
sections 7 of the shift register 5. When signal FSETIN has been
transmitted to all flip-flop sections 7, the shift register 5
supplies signal FSETOUT to the first control section 21. The first
control section 21 receives signal FSETOUT as signal FSET1.
[0097] Signal FCLRIN is transmitted sequentially to the flip-flop
sections 7 of the shift register 5. When signal FCLRIN has been
transmitted to all flip-flop sections 7, the shift register 5
supplies signal FCLROUT to the second control section 22. The
second control section 22 receives signal FCLROUT as signal
FCLR2.
[0098] FIG. 14 is a block diagram showing the configuration of the
first control section 21 depicted in FIG. 13. The first control
section 21 comprises a first resetting signal-generating circuit
21a and a first setting signal-generating circuit 21b. The first
resetting signal-generating circuit 21a receives signal FXOK,
signal FXDONE and signal SCIN. The first resetting
signal-generating circuit 21a outputs signal FCLR1.
[0099] The first setting signal-generating circuit 21b receives
signal FSET1 and outputs signal SSOUT.
[0100] FIG. 15 is a block diagram showing the configuration of the
second control section 22 depicted in FIG. 13. The second control
section 22 comprises a second resetting signal-generating circuit
22a and a second setting signal-generating circuit 22b. The second
resetting signal-generating circuit 22a receives signal FCLR2 and
outputs signal SCOUT.
[0101] The second setting signal-generating circuit 22b receives
signal FCLR2 and signal SSIN and outputs signal FSET2.
[0102] The first resetting signal-generating circuit 21a and the
second resetting signal-generating circuit 22a produce pulse
signals whose polarity is negative ("1".fwdarw."0".fwdarw."1"). The
first setting signal-generating circuit 21b and the second setting
signal-generating circuit 22b produce pulse signals whose polarity
is positive ("0".fwdarw."1".fwdarw."0").
[0103] In the present embodiment, the setting and resetting
operations are controlled by two control sections (namely, the
first control section 21 and the second control section 22).
Needless to say, these control sections may be realized as one
block. In this case, the first resetting signal-generating circuit
21a and the second resetting signal-generating circuit 22a are
realized as one block, and the first setting signal-generating
circuit 21b and the second setting signal-generating circuit 22b
are also realized as one block.
[0104] FIG. 16 is a circuit diagram showing a specific
configuration of the first control section 21 depicted in FIG. 14.
The first control section 21 comprises inverter circuits 30, 31, 36
and 38, an AND circuit 32, NAND circuits 33, 34 and 35, and a delay
element 37. NAND circuits 34 and 35 jointly constitute a holding
circuit. This holding circuit holds the data from inverter circuit
38 when signal FXDONE becomes "1." After being held, the data is
output to NAND circuit 33. The delay element 37 receives the signal
supplied from inverter circuit 36, delays the rising of this signal
for a predetermined time, and then outputs it. The delay time can
be arbitrarily determined in accordance with the number of
flip-flops FF included in the shift register 5.
[0105] FIG. 17 is a circuit diagram showing a specific
configuration of the second control section 22 depicted in FIG. 15.
The second control section 22 comprises an AND circuit 40, NAND
circuits 41 and 42, a delay element 43 and an inverter circuit 44.
NAND circuits 41 and 42 jointly constitute a holding circuit. This
holding circuit holds the data from inverter circuit 44 when signal
FCLROUT (FCLR2) becomes "1." After being held, the data is output.
The delay element 43 delays the rising of signal SSIN for a
predetermined time and then outputs it.
[0106] A description will now be given as to how the semiconductor
integrated circuit 20 operates. FIG. 18 is a timing chart
illustrating the operation of the semiconductor circuit 20. First
of all, signal FXOK rises, and in response thereto, the first
control section 21 raises the level of signal FCLRIN. When this
signal, FCLRIN, is transmitted to signal FCLROUT (i.e. the signal
FCLRIN is output from the shift register 5 as the signal FCLROUT),
all flip-flops FF are released from the reset state.
[0107] In response to the rising of signal FCLROUT, the second
control circuit 22 raises the level of signal FSETIN. Simultaneous
with this, the second control section 22 raises the level of signal
SCOUT (SCIN). When signal FSETIN is transmitted to signal FSETOUT,
the first control section 21 raises the level of signal SSOUT
(SSIN). Upon reception of signal SSIN, the second control section
22 lowers the level of signal FSETIN. Signal FSETIN is transmitted
to signal FSETOUT.
[0108] As a result of the above operation, the data in all
nonvolatile elements is set in flop-flops FF. Then, the data is
transferred to the circuit block group 3.
[0109] After the data transfer operation, signal FXDONE rises. In
response to signal FXDONE, the first control section 21 lowers the
level of signal FCLRIN. When this signal, FCLRIN, is transmitted to
signal FCLROUT, the second control section 22 lowers the level of
signal SCOUT (SCIN). Upon receipt of signal SCIN, the first control
section 21 raises the level of signal FCLRIN.
[0110] Thereafter, the data in the nonvolatile elements is set in
flip-flops FF once again, as it was at the start of the data
transfer operation. After resetting all flip-flops FF at the end of
the data transfer operation in this manner, the data in the
nonvolatile elements can be set in the flop-flops FF.
[0111] The time between the rise of signal SSIN and the fall of
signal FSETIN is provided by the delay element 43. This enables the
pulse signals of signal FSETIN to have a sufficient margin. The
time between the fall of signal SCIN and the rise of signal FCLRIN
is provided by the delay element 37. This enables the pulse signals
of signal FCLRIN to have a sufficient margin.
[0112] As described above, the present embodiment enables pulse
signals, used for setting or resetting the shift registers 5, to be
transmitted to all flip-flops FF of the shift register 5. Hence,
the flip-flops can set or reset data in a reliable manner.
[0113] In addition, since the delay element is used for ensuring a
sufficient pulse width, the pulse signals have a sufficient
margin.
[0114] Additional advantages and modifications will readily occur
to those skilled in the art. Therefore, the invention in its
broader aspects is not limited to the specific details and
representative embodiments shown and described herein. Accordingly,
various modifications may be made without departing from the spirit
or scope of the general inventive concept as defined by the
appended claims and their equivalents.
* * * * *