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US4777586A Expired / Lapsed US ⏱️ 0.0 years remaining

Semiconductor integrated circuit device with built-in arrangement for memory testing

Assignee: Hitachi Ltd
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Filing: 1986-09-22
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Granted: 1988-10-11
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Expires: 2006-09-22
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Abstract

Abstract A semiconductor integrated circuit device which inhibits the output of programmed data of its built-in memory to external terminals but outputs the result of a comparison of the programmed data with an input signal supplied from a first external terminal to a second external terminal.

Inventors

  • 👤 Kiyoshi Matsubara
  • 👤 Tadashi Yamaura

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 10:28
CPC Classifications
G; G06; G06F; G06F15/00; G06F21/00; G06F21/70; G06F21/78; G06F21/79; G11; G11C; G11C29/00; G11C29/04

Claims Analysis

Total Claims: 27
Claim 1
Independent Claim 94 words
A semiconductor integrated circuit device including a plurality of external terminals for receiving signals to be supplied to the device or outputting signals from the device, comprising: a memory circuit, an output of predetermined programmed data of which is inhibited to said external terminals; and a comparing circuit including comparing means for comparing the programmed data read out from said memory circuit with an input signal supplied from a first one of said external terminals, and output means for outputting a resulting coincidence or discordance signal to a second one of said external terminals.
Claim 2
Dependent Claim 94 words
A semiconductor integrated circuit device including a plurality of external terminals for receiving signals to be supplied to the device or outputting signals from the device, comprising: a memory circuit, an output of predetermined programmed data of which is inhibited to said external terminals; and a comparing circuit including comparing means for comparing the programmed data read out from said memory circuit with an input signal supplied from a first one of said external terminals, and output means for outputting a resulting coincidence or discordance signal to a second one of said external terminals.
Claim 3
Dependent Claim 17 words
A semiconductor integrated circuit device according to claim 1, wherein said memory circuit comprises a read-only memory.
Claim 4
Dependent Claim 49 words
A semiconductor integrated circuit device according to claim 1, wherein said coincidence or discordance signal is output once after a plurality of said programmed data is compared with a plurality of input signals supplied from at least the first one of said external terminals corresponding to said programmed data.
Claim 5
Dependent Claim 24 words
A semiconductor integrated circuit device according to claim 3, wherein said programmed data is read out in a unit of a plurality of bits.
Claim 6
Dependent Claim 31 words
A semiconductor integrated circuit device according to claim 3, wherein the output means is coupled to receive address signals and further wherein said output means is controlled by said address signals.
Claim 7
Dependent Claim 33 words
A semiconductor integrated circuit device according to claim 3, wherein the output means is controlled by a counter circuit coupled to the comparing circuit in synchronism with an operation of the comparing means.
Claim 8
Dependent Claim 50 words
A semiconductor integrated circuit device according to claim 3, wherein said comparing circuit includes holding means for holding said coincidence or discordance signal and inhibiting means for inhibiting a reception of subsequent results of comparison after one discordance signal has been generated and is being held by the holding means.
Claim 9
Dependent Claim 55 words
A semiconductor integrated circuit device according to claim 1, which further comprises a processor coupled to the memory circuit via an internal bus and which executes calculation based on said programmed data of said memory circuit, and wherein said memory circuit is comprised of a read-only memory storing therein programs or data for said processor.
Claim 10
Dependent Claim 134 words
A semiconductor integrated circuit device including a plurality of external terminals for receiving signals to be supplied to the device or outputting signals from the device, comprising: a memory circuit, an output of predetermined programmed data of which is inhibited to said external terminals; and a comparing circuit including comparing means for comparing the programmed data read out from said memory circuit with an input signal supplied from a first one of said external terminals, and output means for outputting a resulting coincidence or discordance signal to a second one of said external terminals, wherein said memory circuit and said comparing circuit are both formed on a single chip to allow testing of said memory circuit by operation of said comparing circuit without delivering data from said memory circuit outside of said single chip.
Claim 11
Dependent Claim 134 words
A semiconductor integrated circuit device including a plurality of external terminals for receiving signals to be supplied to the device or outputting signals from the device, comprising: a memory circuit, an output of predetermined programmed data of which is inhibited to said external terminals; and a comparing circuit including comparing means for comparing the programmed data read out from said memory circuit with an input signal supplied from a first one of said external terminals, and output means for outputting a resulting coincidence or discordance signal to a second one of said external terminals, wherein said memory circuit and said comparing circuit are both formed on a single chip to allow testing of said memory circuit by operation of said comparing circuit without delivering data from said memory circuit outside of said single chip.
Claim 12
Dependent Claim 153 words
A microcomputer comprising: a CPU including means for performing predetermined data processing in accordance with a program; a memory means for memorizing information constituting the program; external terminals provided on a semiconductor integrated circuit device in which the microcomputer is formed; a comparing means coupled to at least one of the external terminals and to said memory means for comparing an input signal supplied from said at least one of the external terminals with an output signal read out from the memory means and for forming an output comparing signal based on comparing of said input signal and said output signal; output means coupled to said comparing means for delivering an output signal based on the output comparing signal of the comparing means to at least one of the external terminals; and a bus for connecting at least one of the external terminals with the CPU, the memory means or the comparing means.
Claim 13
Dependent Claim 153 words
A microcomputer comprising: a CPU including means for performing predetermined data processing in accordance with a program; a memory means for memorizing information constituting the program; external terminals provided on a semiconductor integrated circuit device in which the microcomputer is formed; a comparing means coupled to at least one of the external terminals and to said memory means for comparing an input signal supplied from said at least one of the external terminals with an output signal read out from the memory means and for forming an output comparing signal based on comparing of said input signal and said output signal; output means coupled to said comparing means for delivering an output signal based on the output comparing signal of the comparing means to at least one of the external terminals; and a bus for connecting at least one of the external terminals with the CPU, the memory means or the comparing means.
Claim 14
Dependent Claim 20 words
A microcomputer according to claim 10, wherein the comparing means includes a comparing circuit for comparing a plurality of signals.
Claim 15
Dependent Claim 37 words
A microcomputer according to claim 11, wherein the comparing circuit compares a plurality of output signals read out from the memory means with a plurality of input signals supplied from at least one of the external terminals.
Claim 16
Dependent Claim 24 words
A microcomputer according to claim 12, wherein the output means includes a memory circuit for memorizing the output comparing signal of the comparing means.
Claim 17
Dependent Claim 38 words
A microcomputer according to claim 13, wherein the output means includes means for performing a logic function for processing a first output comparing signal of the comparing means and a second output comparing signal of the comparing means.
Claim 18
Dependent Claim 14 words
A microcomputer according to claim 14, wherein the logic function is an AND function.
Claim 19
Dependent Claim 14 words
A microcomputer according to claim 13, wherein the memory circuit comprises a flip-flop circuit.
Claim 20
Dependent Claim 31 words
A microcomputer according to claim 13, the CPU includes means for inhibiting delivery of the output signal read out from the memory means to at least one of the external terminals.
Claim 21
Dependent Claim 44 words
A microcomputer according to claim 10, wherein the microcomputer is formed on a single chip so that operation of the memory means can be tested by operation of said comparing means without delivering information memorized by said memory means outside of said single chip.
Claim 22
Dependent Claim 98 words
An IC card having a semiconductor integrated circuit device including a plurality of external terminals for receiving signals to be supplied to the device or outputting signals from the device, comprising: a memory circuit, an output of predetermined programmed data of which is inhibited to said external terminals; and a comparing circuit including comparing means for comparing the programmed data read out from said memory circuit with an input signal supplied from a first one of said external terminals, and output means for outputting a resulting coincidence or discordance signal to a second one of said external terminals.
Claim 23
Dependent Claim 98 words
An IC card having a semiconductor integrated circuit device including a plurality of external terminals for receiving signals to be supplied to the device or outputting signals from the device, comprising: a memory circuit, an output of predetermined programmed data of which is inhibited to said external terminals; and a comparing circuit including comparing means for comparing the programmed data read out from said memory circuit with an input signal supplied from a first one of said external terminals, and output means for outputting a resulting coincidence or discordance signal to a second one of said external terminals.
Claim 24
Dependent Claim 157 words
An IC card having a microcomputer comprising: a CPU including means for performing predetermined data processing in accordance with a program; a memory means for memorizing information constituting the program; external terminals provided on a semiconductor integrated circuit device in which the microcomputer is formed; a comparing means coupled to at least one of the external terminals and to said memory means for comparing an input signal supplied from said at least one of the external terminals with an output signal read out from the memory means and for forming an output comparing signal based on comparing of said input signal and said output signal; output means coupled to said comparing means for delivering an output signal based on the output comparing signal of the comparing means to at least one of the external terminals; and a bus for connecting at least one of the external terminals with the CPU, the memory means or the comparing means.
Claim 25
Dependent Claim 157 words
An IC card having a microcomputer comprising: a CPU including means for performing predetermined data processing in accordance with a program; a memory means for memorizing information constituting the program; external terminals provided on a semiconductor integrated circuit device in which the microcomputer is formed; a comparing means coupled to at least one of the external terminals and to said memory means for comparing an input signal supplied from said at least one of the external terminals with an output signal read out from the memory means and for forming an output comparing signal based on comparing of said input signal and said output signal; output means coupled to said comparing means for delivering an output signal based on the output comparing signal of the comparing means to at least one of the external terminals; and a bus for connecting at least one of the external terminals with the CPU, the memory means or the comparing means.
Claim 26
Dependent Claim 26 words
A semiconductor device according to claim 2, 3, 4, 5, 6, 7, 8 or 9, wherein said semiconductor integrated circuit device is on an IC card.
Claim 27
Dependent Claim 22 words
A microcomputer according to claim 11, 12, 13, 14, 15, 16, 17 or 18, wherein said microcomputer is on an IC card.

References Cited (Backward Citations)

US4414665A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-10-11 1992-04-11 1992-10-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-10-11 1996-04-11 1996-10-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-10-11 2000-04-11 2000-10-11 $7700.00 Window Closed / Lapsed

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