US20080273406A1 - Enhanced sram redundancy circuit for reducing wiring and required number of redundant elements - Google Patents
Enhanced sram redundancy circuit for reducing wiring and required number of redundant elements Download PDFInfo
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- US20080273406A1 US20080273406A1 US12/172,318 US17231808A US2008273406A1 US 20080273406 A1 US20080273406 A1 US 20080273406A1 US 17231808 A US17231808 A US 17231808A US 2008273406 A1 US2008273406 A1 US 2008273406A1
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C29/00—Checking stores for correct operation ; Subsequent repair; Testing stores during standby or offline operation
- G11C29/70—Masking faults in memories by using spares or by reconfiguring
- G11C29/78—Masking faults in memories by using spares or by reconfiguring using programmable devices
- G11C29/84—Masking faults in memories by using spares or by reconfiguring using programmable devices with improved access time or stability
- G11C29/846—Masking faults in memories by using spares or by reconfiguring using programmable devices with improved access time or stability by choosing redundant lines at an output stage
Definitions
- the present invention relates generally to the data processing field, and more particularly, relates to a method and enhanced Static Random Access Memory (SRAM) redundancy circuit to reduce wiring and the required number of redundant elements.
- SRAM Static Random Access Memory
- FIGS. 1 , 2 , and 3 a prior art SRAM redundancy arrangement is shown.
- This conventional SRAM redundancy arrangement can only swap out defective cells starting on an even column. This necessitated using four redundant columns labeled R in FIG. 1 to cover all required repairs, including repairs between any two columns.
- the prior art SRAM redundancy circuit includes a plurality of pairs of series connected 2 : 1 multiplexers (MUXs). Each pair of series connected MUXs is connected to an adjacent pair of odd and even SRAM columns.
- the first MUX of a pair of MUXs is a bit decode MUX, each of the first MUXs receiving a select bit (BS).
- BS select bit
- Redundancy steering is provided with the second MUX after the first bit decode MUX in the prior art arrangement. Replacements are provided only on even bits, and that in turn forces the need for 4 redundant elements. For example, as indicated by an X between columns 1 and 2 in FIG. 1 , a shift of four bits are needed for any 2 bit replacement, as schematically illustrated above the columns 2 , 3 , 4 , and 5 .
- FIG. 2 shows a prior art predecoder block that feeds the prior art SRAM redundancy decode circuits shown in FIG. 3 .
- the prior art SRAM redundancy decode circuits as shown in FIG. 3 include 64 redundant decode circuits, one for each even SRAM column in a SRAM design with 128 columns.
- a standard 2 to 4 address predecoder illustrated in FIG. 2 is used to generate the inputs to the first stage of the redundant decode circuit.
- a redundant enable (RED-EN) is applied to a buffer that provides a redundancy decode signal RED_BL_MASTER.
- a steering input STEER_T_MINUS_ 1 is applied to an inverter 302 .
- the predecoded bits labeled GROUP 01, GROUP 23, GROUP 45 are applied to a 3-input NAND 304 .
- the output of inverter 302 and NAND 304 are applied to a NAND 306 .
- the output of NAND 306 and the redundancy decode signal RED_BL_MASTER is applied to a NAND 308 .
- NAND 308 generates a STEER_C signal that is inverted by an inverter 310 generating a STEER_T signal.
- the redundancy address decodes to the first column to be shifted or steered.
- each stage feeds the results of its decode to the next decoders 300 , #0-63, such that once the decoded one is found it forces all subsequent decodes to be true. Every column after that one is then shifted and at the end the redundant elements are steered in.
- redundancy decode signal RED_BL_MASTER requires a respective separate wire for connection to each of the decoders 300 , #0-63.
- Principal aspects of the present invention are to provide a method and enhanced Static Random Access Memory (SRAM) redundancy circuit to reduce wiring and the required number of redundant elements.
- Other important aspects of the present invention are to provide such method and enhanced Static Random Access Memory (SRAM) redundancy circuit to reduce wiring and the required number of redundant elements substantially without negative effect and that overcome some of the disadvantages of prior art arrangements.
- SRAM Static Random Access Memory
- a bitline redundancy mechanism allows the swapping of a pair of bitlines for a redundant pair.
- the bit columns are interleaved with respective even and odd bits, two of the adjacent bits are swapped out at a time, one even and one odd.
- the swap is accomplished by steering the data around the bad columns and adding redundant columns on the end that are steered in when needed.
- a single multiplexer provides redundancy steering incorporated with bit decode.
- a bit select (BS) and a redundancy steer select (RS ⁇ 0:1>) are combined to provide steering around a bad column and adding redundant columns in the SRAM redundancy circuit.
- FIGS. 1 , 2 , and 3 illustrates a prior art SRAM redundancy arrangement
- FIG. 4 illustrates an exemplary SRAM redundancy circuit in accordance with the preferred embodiment
- FIGS. 5A and 5B together illustrate an exemplary 4:1 multiplexer (MUX) of the SRAM redundancy circuit of FIG. 4 in accordance with the preferred embodiment
- FIG. 6 illustrates exemplary SRAM redundancy decode circuits in accordance with the preferred embodiment
- FIGS. 7A and 7B together illustrate an exemplary 2:4 predecoder used with the SRAM redundancy decode circuits of FIG. 6 in accordance with the preferred embodiment.
- a method and enhanced Static Random Access Memory (SRAM) redundancy circuit are provided to reduce wiring and the required number of redundant elements.
- a bitline redundancy mechanism allows the swapping of a pair of bitlines for a good set. By enabling the decode to occur at any column, all required repairs may be made with only two redundant columns.
- the bit columns are interleaved with even and odd bits; two of the adjacent bits are swapped out at a time, one even and one odd.
- the swap is accomplished by steering the data around the bad columns and adding redundant columns on the end that are steered in when needed.
- a single multiplexer (MUX) provides redundancy steering incorporated with bit decode. In the redundancy steering bit decode of the invention, it is guaranteed that once steering is started, all bits thereafter are steered as required.
- the prior art requires 64 redundant decode circuits, one for each even column.
- the invention has higher granularity, using 128 redundant decode circuits.
- Both the prior art and the invention use standard 2 to 4 address predecoders to generate the inputs to the first stage of the redundant decode circuit.
- the redundant address decodes to the first column to be shifted or steered. Every column after that one is then shifted and at the end the redundant elements are steered in.
- SRAM redundancy circuit 400 includes a plurality of SRAM columns 402 including a pair of redundancy SRAM columns labeled R.
- a single 4:1 multiplexer (MUX) 404 provides redundancy steering incorporated into a bit decode. Each MUX 404 is used instead of the two 2:1 MUXs in series of the prior art arrangement of FIG. 1 .
- Each MUX 404 receives a select bit (BS) and the redundancy select RS ⁇ 0:1>.
- Each column 402 is fed into two of the 4:1 MUXs, with the exception of the first two columns 0 , 1 .
- the output from column 0 , 402 goes to A of the first MUX 404
- column 1 goes to B of the first MUX 404
- column 2 goes to C of first MUX 404 and to A of the second MUX 404
- column 3 goes to D of first MUX 404 and B of second MUX 404 , and the like.
- each 4:1 MUX 404 has 3 selector inputs (BS, RS ⁇ 0> and RS ⁇ 1>).
- BS is the same select bit as in prior art as shown FIG. 1 .
- RS ⁇ 0:1> are steering selects provided by the decoder circuits illustrated in FIG. 6 .
- X between columns 1 and 2 in FIG. 4
- a shift of two bits are needed for any 2 bit replacement, as schematically illustrated above the columns 1 and 2 .
- FIGS. 5A and 5B together illustrate an exemplary 4:1 multiplexer (MUX) 404 of the SRAM redundancy circuit 400 of FIG. 4 in accordance with the preferred embodiment.
- MUX 4:1 multiplexer
- Element E, 500 includes a first inverter 502 receiving an A input, and a second inverter 504 receiving an input S.
- Element E, 500 includes a parallel-connected P-channel field effect transistor (PFET) 506 and N-channel field effect transistor (NFET) 508 providing an output Z.
- PFET P-channel field effect transistor
- NFET N-channel field effect transistor
- Second inverter 504 provides a gate input to PFET 506 and input S connects to a gate input of NFET 508 .
- 4:1 MUX 404 includes a plurality of elements E #1-4, 500 receiving a respective input A, B, C, D and the input S.
- Selector inputs BS, RS ⁇ 0> and RS ⁇ 1> are applied via logic function defined by a plurality of invertors 510 , 512 , 514 , 516 , and a plurality of AND gates 520 , 522 , 524 , 526 .
- Input BS is applied to AND gates 522 , 526 , and is inverted and applied to AND gates 520 , 524 .
- the redundancy select RS ⁇ 0> is applied to AND gate 524 and is inverted and applied to AND gate 520 .
- the redundancy select RS ⁇ 1> is applied to AND gate 526 and is inverted and applied to AND gate 522 .
- a respective output S of AND gates 520 , 522 , 524 , 526 is applied to the input S of elements E #1-4, 500 .
- An output Z of respective elements E #1-4, 500 is applied to an inverter 530 , providing anon-inverted output of the 4:1 MUX 404 .
- the bit select (BS) and the redundancy steer select (RS ⁇ 0:1>) are combined to properly select the correct bit.
- the MUX 404 takes the bit from two columns over and starts steering with every bit thereafter being steered, and two columns are never steered into the same MUX output.
- SRAM redundancy circuit 400 with MUX 404 provides a significant change from the prior art SRAM redundancy circuit of FIG. 1 , which caused a shift of 4 bits for any 2 bit replacement.
- SRAM redundancy decode 600 includes 128 redundant decode circuits 602 , #0-127.
- SRAM redundancy decode 600 includes one redundant decode circuits 602 for each even and odd SRAM column in a SRAM design with 128 columns.
- a standard 2 to 4 address predecoder illustrated in FIGS. 7A and 7B is used to generate the inputs to the redundant decode circuits 602 .
- An embedded redundant enable is applied to an input each of the 128 redundant decode circuits 602 .
- An additional wire advantageously is saved by embedding the redundancy enable into the decode 602 , as compared to the prior art decode circuits illustrated in FIG. 3 .
- Each of the 128 redundant decode circuits 602 , #0-127 includes a pair of NAND gates 604 , 606 respectively receiving inputs A, B and C, D and having a respective output applied to an OR gate 608 .
- the output of OR gate 608 and a decode signal SN_M 1 is applied to a NAND 610 .
- NAND 610 generates a signal that is sequentially inverted by a pair of series connected inverters 612 , 614 to generate an output S signal.
- the redundant address decodes to the first column to be shifted or steered.
- each stage 602 , #0-127 feeds the results SN_M 1 of its decode at node TN at the output of the first inverter 612 to the next respective one of the decoders 602 , #0-127.
- FIGS. 7A and 7B together illustrate an exemplary 2:4 predecoder generally designated by the reference character 700 for use with the SRAM redundancy decode 600 of FIG. 6 in accordance with the preferred embodiment.
- the 2:4 predecoder 700 receives a redundant enable signal RED-ED applied to an enable input EN.
- the 2:4 predecoder 700 includes a pair of inverters 702 , 704 respectively receiving the A input and the B input.
- the outputs of inverters 702 , 704 and the A input and the B input are applied to respective inputs of a plurality of 3-input NAND gates 706 , 708 , 710 , 712 , as shown.
- the redundant enable input EN is applied to an input of each of 3-input NAND gates 706 , 708 , 710 , 712 .
- each of 3-input NAND gates 706 , 708 , 710 , 712 is applied to a respective one of a plurality of inverters 714 , 716 , 718 , 720 providing outputs Z 0 , Z 1 , Z 2 , Z 3 .
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- For Increasing The Reliability Of Semiconductor Memories (AREA)
- Static Random-Access Memory (AREA)
Abstract
A method and enhanced Static Random Access Memory (SRAM) redundancy circuit reduce wiring and the required number of redundant elements. A bitline redundancy mechanism allows the swapping of a pair of bitlines for a redundant pair of bit columns. Two of the adjacent bitlines are swapped out at a time, one even and one odd. The swap is accomplished by steering the data around the bad columns and adding redundant columns on the end that are steered in when needed.
Description
- The present invention relates generally to the data processing field, and more particularly, relates to a method and enhanced Static Random Access Memory (SRAM) redundancy circuit to reduce wiring and the required number of redundant elements.
- Referring to
FIGS. 1 , 2, and 3, a prior art SRAM redundancy arrangement is shown. This conventional SRAM redundancy arrangement can only swap out defective cells starting on an even column. This necessitated using four redundant columns labeled R inFIG. 1 to cover all required repairs, including repairs between any two columns. - As shown in
FIG. 1 , the prior art SRAM redundancy circuit includes a plurality of pairs of series connected 2:1 multiplexers (MUXs). Each pair of series connected MUXs is connected to an adjacent pair of odd and even SRAM columns. The first MUX of a pair of MUXs is a bit decode MUX, each of the first MUXs receiving a select bit (BS). In operation, all the first MUXs take input A, the even SRAM column; or all take input B, the odd SRAM column. With a BS=0, the A input is selected and BS=1, the B input is selected. - Redundancy steering is provided with the second MUX after the first bit decode MUX in the prior art arrangement. Replacements are provided only on even bits, and that in turn forces the need for 4 redundant elements. For example, as indicated by an X between
columns FIG. 1 , a shift of four bits are needed for any 2 bit replacement, as schematically illustrated above thecolumns -
FIG. 2 shows a prior art predecoder block that feeds the prior art SRAM redundancy decode circuits shown inFIG. 3 . The prior art SRAM redundancy decode circuits as shown inFIG. 3 include 64 redundant decode circuits, one for each even SRAM column in a SRAM design with 128 columns. A standard 2 to 4 address predecoder illustrated inFIG. 2 is used to generate the inputs to the first stage of the redundant decode circuit. A redundant enable (RED-EN) is applied to a buffer that provides a redundancy decode signal RED_BL_MASTER. In each of the 64 bit decode circuits, a steering input STEER_T_MINUS_1 is applied to aninverter 302. The predecoded bits labeledGROUP 01,GROUP 23,GROUP 45 are applied to a 3-input NAND 304. The output ofinverter 302 andNAND 304 are applied to aNAND 306. The output ofNAND 306 and the redundancy decode signal RED_BL_MASTER is applied to aNAND 308. NAND 308 generates a STEER_C signal that is inverted by aninverter 310 generating a STEER_T signal. In operation, the redundancy address decodes to the first column to be shifted or steered. Then each stage feeds the results of its decode to the next decoders 300, #0-63, such that once the decoded one is found it forces all subsequent decodes to be true. Every column after that one is then shifted and at the end the redundant elements are steered in. - In addition to requiring four redundant columns to cover all required repairs the prior art arrangement, another disadvantage is that the redundancy decode signal RED_BL_MASTER requires a respective separate wire for connection to each of the decoders 300, #0-63.
- Principal aspects of the present invention are to provide a method and enhanced Static Random Access Memory (SRAM) redundancy circuit to reduce wiring and the required number of redundant elements. Other important aspects of the present invention are to provide such method and enhanced Static Random Access Memory (SRAM) redundancy circuit to reduce wiring and the required number of redundant elements substantially without negative effect and that overcome some of the disadvantages of prior art arrangements.
- In brief, a method and enhanced Static Random Access Memory (SRAM) redundancy circuit are provided to reduce wiring and the required number of redundant elements. A bitline redundancy mechanism allows the swapping of a pair of bitlines for a redundant pair. The bit columns are interleaved with respective even and odd bits, two of the adjacent bits are swapped out at a time, one even and one odd. The swap is accomplished by steering the data around the bad columns and adding redundant columns on the end that are steered in when needed.
- In accordance with features of the invention, only two redundant columns are required to replace a defect that includes two bad columns. With a SRAM including 128 columns, 128 redundant decode circuits are used. An embedded redundant enable is applied to an input each of the 128 redundant decode circuits and thereby an additional wire advantageously is saved by embedding the redundancy enable as compared to prior art arrangements.
- In accordance with features of the invention, a single multiplexer (MUX) provides redundancy steering incorporated with bit decode. A bit select (BS) and a redundancy steer select (RS<0:1>) are combined to provide steering around a bad column and adding redundant columns in the SRAM redundancy circuit.
- The present invention together with the above and other objects and advantages may best be understood from the following detailed description of the preferred embodiments of the invention illustrated in the drawings, wherein:
-
FIGS. 1 , 2, and 3 illustrates a prior art SRAM redundancy arrangement; -
FIG. 4 illustrates an exemplary SRAM redundancy circuit in accordance with the preferred embodiment; -
FIGS. 5A and 5B together illustrate an exemplary 4:1 multiplexer (MUX) of the SRAM redundancy circuit ofFIG. 4 in accordance with the preferred embodiment; -
FIG. 6 illustrates exemplary SRAM redundancy decode circuits in accordance with the preferred embodiment; and -
FIGS. 7A and 7B together illustrate an exemplary 2:4 predecoder used with the SRAM redundancy decode circuits ofFIG. 6 in accordance with the preferred embodiment. - In accordance with features of the invention, a method and enhanced Static Random Access Memory (SRAM) redundancy circuit are provided to reduce wiring and the required number of redundant elements. A bitline redundancy mechanism allows the swapping of a pair of bitlines for a good set. By enabling the decode to occur at any column, all required repairs may be made with only two redundant columns. The bit columns are interleaved with even and odd bits; two of the adjacent bits are swapped out at a time, one even and one odd. The swap is accomplished by steering the data around the bad columns and adding redundant columns on the end that are steered in when needed. A single multiplexer (MUX) provides redundancy steering incorporated with bit decode. In the redundancy steering bit decode of the invention, it is guaranteed that once steering is started, all bits thereafter are steered as required.
- In accordance with features of the invention, only two redundant columns are required to replace a defect including two defective columns. Assuming a SRAM design with 128 columns, the prior art requires 64 redundant decode circuits, one for each even column. The invention has higher granularity, using 128 redundant decode circuits. Both the prior art and the invention use
standard 2 to 4 address predecoders to generate the inputs to the first stage of the redundant decode circuit. The redundant address decodes to the first column to be shifted or steered. Every column after that one is then shifted and at the end the redundant elements are steered in. - Having reference now to the drawings, in
FIG. 4 , there is shown an exemplary SRAM redundancy circuit generally designated by thereference character 400 in accordance with the preferred embodiment.SRAM redundancy circuit 400 includes a plurality ofSRAM columns 402 including a pair of redundancy SRAM columns labeled R. A single 4:1 multiplexer (MUX) 404 provides redundancy steering incorporated into a bit decode. EachMUX 404 is used instead of the two 2:1 MUXs in series of the prior art arrangement ofFIG. 1 . - Each
MUX 404 receives a select bit (BS) and the redundancy select RS<0:1>. Eachcolumn 402 is fed into two of the 4:1 MUXs, with the exception of the first twocolumns column first MUX 404,column 1 goes to B of thefirst MUX 404,column 2 goes to C offirst MUX 404 and to A of thesecond MUX 404,column 3 goes to D offirst MUX 404 and B ofsecond MUX 404, and the like. Note that each 4:1MUX 404 has 3 selector inputs (BS, RS<0> and RS<1>). BS is the same select bit as in prior art as shownFIG. 1 . RS<0:1> are steering selects provided by the decoder circuits illustrated inFIG. 6 . For example, as indicated by an X betweencolumns FIG. 4 , a shift of two bits are needed for any 2 bit replacement, as schematically illustrated above thecolumns -
FIGS. 5A and 5B together illustrate an exemplary 4:1 multiplexer (MUX) 404 of theSRAM redundancy circuit 400 ofFIG. 4 in accordance with the preferred embodiment. - Referring now to
FIG. 5A , an element E, 500 is shown that is used to construct the 4:1MUX 404. Element E, 500 includes afirst inverter 502 receiving an A input, and asecond inverter 504 receiving an input S. Element E, 500 includes a parallel-connected P-channel field effect transistor (PFET) 506 and N-channel field effect transistor (NFET) 508 providing an output Z.Second inverter 504 provides a gate input to PFET 506 and input S connects to a gate input ofNFET 508. - Referring also to
FIG. 5B , 4:1MUX 404 includes a plurality of elements E #1-4, 500 receiving a respective input A, B, C, D and the input S. Selector inputs BS, RS<0> and RS<1> are applied via logic function defined by a plurality ofinvertors gates gates gates gate 524 and is inverted and applied to ANDgate 520. The redundancy select RS<1> is applied to ANDgate 526 and is inverted and applied to ANDgate 522. A respective output S of ANDgates inverter 530, providing anon-inverted output of the 4:1MUX 404. - In accordance with features of the invention, the bit select (BS) and the redundancy steer select (RS<0:1>) are combined to properly select the correct bit. Essentially, when a steering bit is present, the
MUX 404 takes the bit from two columns over and starts steering with every bit thereafter being steered, and two columns are never steered into the same MUX output.SRAM redundancy circuit 400 withMUX 404 provides a significant change from the prior art SRAM redundancy circuit ofFIG. 1 , which caused a shift of 4 bits for any 2 bit replacement. - Referring now to
FIG. 6 , there is shown an exemplary SRAM redundancy decode generally designated by thereference character 600 in accordance with the preferred embodiment.SRAM redundancy decode 600 includes 128redundant decode circuits 602, #0-127.SRAM redundancy decode 600 includes oneredundant decode circuits 602 for each even and odd SRAM column in a SRAM design with 128 columns. A standard 2 to 4 address predecoder illustrated inFIGS. 7A and 7B is used to generate the inputs to theredundant decode circuits 602. - An embedded redundant enable is applied to an input each of the 128
redundant decode circuits 602. An additional wire advantageously is saved by embedding the redundancy enable into thedecode 602, as compared to the prior art decode circuits illustrated inFIG. 3 . - Each of the 128
redundant decode circuits 602, #0-127 includes a pair ofNAND gates OR gate 608. The output of ORgate 608 and a decode signal SN_M1 is applied to aNAND 610.NAND 610 generates a signal that is sequentially inverted by a pair of series connectedinverters stage 602, #0-127 feeds the results SN_M1 of its decode at node TN at the output of thefirst inverter 612 to the next respective one of thedecoders 602, #0-127. -
FIGS. 7A and 7B together illustrate an exemplary 2:4 predecoder generally designated by thereference character 700 for use with the SRAM redundancy decode 600 ofFIG. 6 in accordance with the preferred embodiment. The 2:4predecoder 700 receives a redundant enable signal RED-ED applied to an enable input EN. - Referring now to
FIG. 7B , the 2:4predecoder 700 includes a pair ofinverters inverters input NAND gates input NAND gates input NAND gates inverters - While the present invention has been described with reference to the details of the embodiments of the invention shown in the drawing, these details are not intended to limit the scope of the invention as claimed in the appended claims.
Claims (13)
1. A Static Random Access Memory (SRAM) redundancy circuit including interleaved bit columns with a respective even and odd bits, the SRAM redundancy circuit comprising:
a bitline redundancy mechanism swapping a pair of bitlines for a redundant bitline pair;
said bitline redundancy mechanism swapping two of the adjacent bitlines at a time, one even and one odd by steering the data around at least one bad column and adding two redundant columns.
2. The SRAM circuit as recited in claim 1 includes a plurality of redundancy decode circuits.
3. The SRAM circuit as recited in claim 2 includes an embedded redundant enable applied to an input of each of said plurality of redundant decode circuits.
4. The SRAM circuit as recited in claim 1 includes a multiplexer providing redundancy steering incorporated with bit decode.
5. The SRAM circuit as recited in claim 4 includes logic function combining a bit select (BS) and a redundancy steer select (RS<0:1>) to provide a select input to said multiplexer.
6. The SRAM circuit as recited in claim 1 includes a SRAM redundancy decode including a plurality of redundancy decode circuits, and an address predecoder generating inputs applied to said plurality of redundancy decode circuits.
7. The SRAM circuit as recited in claim 6 includes a redundant enable signal applied to said address predecoder.
8. The SRAM circuit as recited in claim 7 wherein said address predecoder provides an embedded redundant enable applied to an input of each of said plurality of redundancy decode circuits.
9-12. (canceled)
13. A SRAM redundancy circuit comprising:
a plurality of interleaved SRAM bit columns of respective even and odd bits;
a multiplexer providing redundancy steering incorporated with bit decode; said multiplexer coupled to said interleaved SRAM bit columns;
a bit select (BS) and a redundancy steer select (RS<0:1>) providing a select input to said multiplexer;
a plurality of redundancy decode circuits, and
an address predecoder generating inputs applied to said plurality of redundancy decode circuits.
14. The SRAM redundancy circuit as recited in claim 13 wherein said address predecoder applies an embedded redundant enable to an input of each of said redundancy decode circuits.
15. The SRAM redundancy circuit as recited in claim 13 wherein said plurality of redundancy decode circuits includes a respective redundancy decode circuit for each said SRAM bit columns.
16. The SRAM redundancy circuit as recited in claim 13 includes a redundant enable signal applied to said address predecoder.
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US12/172,318 US20080273406A1 (en) | 2006-11-14 | 2008-07-14 | Enhanced sram redundancy circuit for reducing wiring and required number of redundant elements |
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US11/559,431 US7443744B2 (en) | 2006-11-14 | 2006-11-14 | Method for reducing wiring and required number of redundant elements |
US12/172,318 US20080273406A1 (en) | 2006-11-14 | 2008-07-14 | Enhanced sram redundancy circuit for reducing wiring and required number of redundant elements |
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US12/172,318 Abandoned US20080273406A1 (en) | 2006-11-14 | 2008-07-14 | Enhanced sram redundancy circuit for reducing wiring and required number of redundant elements |
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US8879328B2 (en) | 2013-03-15 | 2014-11-04 | Qualcomm Incorporated | Sense amplifier column redundancy |
US9583211B1 (en) | 2016-06-01 | 2017-02-28 | International Business Machines Coproration | Incorporating bit write capability with column interleave write enable and column redundancy steering |
US9721628B1 (en) | 2016-09-15 | 2017-08-01 | Globalfoundries Inc. | Address based memory data path programming scheme |
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US7826285B2 (en) * | 2007-09-12 | 2010-11-02 | International Business Machines Corporation | Memory column redundancy scheme |
US7773437B2 (en) * | 2007-09-12 | 2010-08-10 | International Business Machines Corporation | Design structure for improved memory column redundancy scheme |
US8427894B2 (en) | 2010-09-21 | 2013-04-23 | International Business Machines Corporation | Implementing single bit redundancy for dynamic SRAM circuit with any bit decode |
US8451668B1 (en) | 2011-12-01 | 2013-05-28 | International Business Machines Corporation | Implementing column redundancy steering for memories with wordline repowering |
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US8879328B2 (en) | 2013-03-15 | 2014-11-04 | Qualcomm Incorporated | Sense amplifier column redundancy |
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US9721628B1 (en) | 2016-09-15 | 2017-08-01 | Globalfoundries Inc. | Address based memory data path programming scheme |
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US20080112237A1 (en) | 2008-05-15 |
US7443744B2 (en) | 2008-10-28 |
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