CTL - redundancy Saman, Slimane, Gary, Rajat Last Updated : June 11, 2010

Section – I Reference Memory Description provided by Gary - used in the definition of each proposal

Memory Architecture 8224 words, 14 bits, mux 16 Bit 0Bit 6Bit 7Bit 14 Rows 0 thru 511 Rows 512 and group of 8 spare columns (left half) 1 group of 8 spare columns (right half) 2 Spare rows (Bottom Bank) 2 Spare rows (Top Bank)

Spare Elements Any spare row in bottom bank can repair any row in the bottom bank Any spare row in the top bank can repair either of the rows (only 2) in the top bank Any group of 8 columns in left array can be repaired Any group of 8 columns in the right array can be repaired

Section – II CTL Syntax lists all proposals and resolution on each

CTL Environment Signals { “Q”[13..0] Out; “A”[13..0] In;“D”[13..0] In; “CRE1” In; “FBA1” [3..0] In “CRE2” In; “FBA2” [3..0] In “RRE1” In “FRA1”[8..0] In “RRE2” In; “FRA2”[8..0] In; “RRE3” In; “FRA3” In; “RRE4” In; “FRA4” In } Environment “myStrangeMemory” { CTL { CRE1 { DataType RepairEnable {ActiveState ForceUp;}} FBA1[3] { DataType RepairAddress;} FBA1[2..0] {DataType RepairDataBit; { ValueRange 0 6; } } CRE2 { DataType RepairEnable {ActiveState ForceUp;}} FBA2[3] { DataType RepairAddress;} FBA2[2..0] {DataType RepairDataBit; { ValueRange 0 6; } } RRE1 {DataType RepairEnable {ActiveState ForceUp;}} FRA1[8..0] {DataType RepairAddress;} RRE2 {DataType RepairEnable {ActiveState ForceUp;}} FRA2[8..0] {DataType RepairAddress;} RRE3 {DataType RepairEnable {ActiveState ForceUp;}} FRA3 {DataType RepairAddress;} RRE4 {DataType RepairEnable {ActiveState ForceUp;}} FRA4 {DataType RepairAddress;} }

CTL – Memory Repair (1) MemoryProperties { SimultaneousReadWrite None; ColumnMultiplexing 16; TopologicalOrg Adjacent; } MemoryRepair{ RepairResource Column1 { RepairType Column; AccessSignals ‘CRE1 + FBA1[3..0]’ Width 8 AddressMap xxxxxxxxxxrxxx DataBitMap 0rrr | DataBitMap xxxxxxx_rrrrrrr } RepairResource Column2 { RepairType Column; AccessSignals ‘CRE2 + FBA2[3..0]’ Width 8 AddressMap xxxxxxxxxxrxxx DataBitMap 1rrr } Uses the traditional map vector 0|1|r|x Uses ValueRange to restrict the bits range Advantage –bit to bit mapping according to the data/address range Limitations –When data are large possible confusion –The above notation cannot describe if multiple repair resources map to unequal segments of a memory. for e.g. the following memory cannot be described –two redundant columns in a 128 column memory, where first redundant column can repair any one of first 32 columns and the second can repair an of th column. status : discarded

CTL – Memory Repair (2) MemoryProperties { SimultaneousReadWrite None; ColumnMultiplexing 16; TopologicalOrg Adjacent; } MemoryRepair{ RepairResource Column1 { RepairType Column; AccessSignals ‘CRE1 + FBA1[3..0]’ Width 8 ColumnAddressMap [15..0] | [3] /* map the column address only */ DataMap [6..0] } RepairResource Column2 { RepairType Column; AccessSignals ‘CRE2 + FBA2[3..0]’ Width 8 ColumnAddressMap [15..0] | [3] DataMap [13..7] } does not rely on ValueRange use an interval format [TopRange..BottomRange] Limitations –Repair resource width > 1 issue –Cannot effectively describe restrictions on the repair resource on repair of set of ‘n’ columns Status : discarded

CTL – Memory Repair (3) MemoryProperties { SimultaneousReadWrite None; ColumnMultiplexing 16; TopologicalOrg Adjacent; } MemoryRepair{ RepairResource Column1 { RepairType Column; AccessSignals ‘CRE1 + FBA1[3..0]’ Width 8 AddressMap {8, 0} | 8n (starting addresses 0 or 8), // we use the generic notation: Starting_adds = p*n+q // p, and q can take any value provided that // starting_adds belong to ColumnAddressRange range ColumnAddressRange [15..0] //Optional – redundant information in this case RowAddressRange [513:0] //Can we have RowAddressRange along with this? DataRange [6..0] } RepairResource Column2 { RepairType Column; AccessSignals ‘CRE2 + FBA2[3..0]’ Width 8 AddressMap 8n ColumnAddressRange [15..0] //Redundant information? DataRange [7..13] } Uses syntax 2 but with clear distinction between address ranges and address maps Resolve syntax 1b limitations using addressMap Status : Property names revised – documented in (4)

CTL – Memory Repair (4) MemoryRepair { // one block summarizing all repair info of the corresponding memory RepairResource { // 1 RepairResource block per spare unit // Defines reparability with the redundancy element Type ; Width // width of the resource, defaulted to 1 AddressMap // defines the possible starting addresses of that element p, and q can take any value provided that // starting_add belong to Column/Row AddressRange RowAddressRange [A..B[, C..D]] // required if the spare unit has restriction on the rows to replace - refers to the logical address ColumnAddressRange [E..F[, G..H]] // required if the spare unit has restriction on columns to replace – refers to the logical address DataRange [I..J[, K..L]] // required if the spare unit has restriction on the data I/O to replace } Replaced RepairType with Type Added multiple range to support logical values for Row/Column/Data range – itc’08 feedback Status : Active proposal

CTL –Repair Access (1) RepairMap Map1 { // Define how to repair the memory FBA1[3] = A1[3]; FBA1[000] = D[0]; // We need to find a way to show the encoding FBA1[001] = D[1]; FBA1[010] = D[2]; // repeat for all Data bits …. // Proposal to use specific notations Bi for Binary Encoding, i for integer // FBA1[B(i)] = D[i]; } multiple interpretation in representation of FBA[i] = Signal For address ‘i’ is index of FBA and signal is the port whose value should be used For IO ‘i’ is value for FBA and signal is the IO repaired Status : Discarded.

CTL –Repair Access (2) RepairConnectivity { //Syntax:// = [ ] [ ] EnableConnectivity CRE1= 1 AddressConnectivity { FBA1[3] = A[3]} DataBitConnectivity { FBA1[2..0] = Bin (D[6..0])} } Proposal to define the repair mechanism in 3 section viz. Enable Connectivity, Address Connectivity, DataConnectivity Status : Revised to make the three properties symmetric

CTL –Repair Access (3) EnableConnectivity {// Defines enable state of redundancy element {RepairValue= ;} } DataConnectivity { // Defines data bit dependency – Primarily used for column repair { RepairValue= ; AssociatedSignal={ }} + } } AddressConnectivity {// Defines address dependency - Primarily used for row / IO repair { {RepairSignal= ;} } Status : pre-review itc’09 allow all properties in each connectivity block

// Defines memory repair data // Generic Syntax : { {RepairSignal= ; RepairValue= ; AssociatedSignal={ }} + } // RepairSignal : Defines the memory signal that defines repair value for RepairPort // RepairValue : Defines a fixed repair value for RepairPort // AssociatedSignal : Defines the associated memory port – always used with RepairValue EnableConnectivity {// Defines enable state of redundancy element { {RepairSignal= ; RepairValue= ; AssociatedSignal={ }} + } } DataConnectivity { // Defines data bit dependency – Primarily used for column repair { {RepairSignal= ; RepairValue= ; AssociatedSignal={ }} + } } AddressConnectivity {// Defines address dependency - Primarily used for row / IO repair { {RepairSignal= ; RepairValue= ; AssociatedSignal={ }} + } } CTL –Repair Access (4) Status : Active proposal

CTL – Multi Port (1) RepairSignalDefinition grp1 { RepairAddress[5] = Add[6]; RepairAddress[4..0] = Add[4..0]; Relation { RepairSignaMap grp1 Port 0; RepairSignaMap grp1 Port 1; } // … Incomplete (just for demonstration of the format AddressConnectivity { FAT[5:0] {RepairSignal = RepairAddress[5:0]]} } Proposal was to define a new block called RepairSignalDefinition Defined a generic repairAddressBus that should be used in each connectivity block RepairAddress itself is mapped to signal pins for each port through generic keyword Add/ Data Status : Discarded since we do not require additional variable called RepairAddress, instead updated the proposal to use Add/Data directly in connectivity blocks

CTL – Multi Port (2) PortMap { { RepairRessources { } // (Optional) specifies the list of available resources for that port. If not all resources are assumed DataMap { // = Data [3:0] = DA[0:3]; } AddressMap { = // Address [7:0] = AA [8:1]; } // … Incomplete (just for demonstration of the format AddressConnectivity { FAT[5:0] {RepairSignal = Address[5:0]]} } Defines keyword Address / Data for defining connectivity blocks PortMap associates “Address/Data” with each port’s signal pins Status : Active

CTL – Serial I/f (1) RepairScanStructures { scanChain { scanLength scanCells “FAT[5..0]:FET:FAB[5..0]:FEB”; scanIn fdi; scanOut fdo; scanClock fclk; scanEnable reset }.. Incomplete & for illustration of format AddressConnectivity { FAT[5] {RepairSignal = A[6]]} FAT[4:0] {RepairSignal = A[4:0]]} } Defines Fuse registers re-using the scan-chain description in CTL * scanCells defines the order of signals used in the connectivity blocks Status : Revised per discussion on Fri Jun 11 th RepairScanStructures should be replaced with repairSerialStructures All properties within repairSerialStructures to be named as register<> instead of scan<> to avoid interpretation clash with atpg scan chains reset state value should be defined for each cell in internal shift register for which new property registerCellResetState was defined.

CTL – Serial I/f (2) RepairSerialStructures { registerChain // Internal shift register name registerLength // Internal shift register length registerCells “FAT[5..0]:FET:FAB[5..0]:FEB:Unused:TIE0”; // Signal order mapping to internal registers. Direction registerIn  registerOut registerIn // data input for internal shift register registerout // data output of internal shift register registerShiftClock // shift clock for internal register registerUpdateClock // update clock for internal shift register registerShiftEnable // shift enable for internal shift register reset // reset pin for internal shift register registerCellResetState // reset state of internal shift register }.. Incomplete & for illustration of format AddressConnectivity { FAT[5] {RepairSignal = A[6]]} FAT[4:0] {RepairSignal = A[4:0]]} } EnableConnectivity { // Defines enable state of redundancy element TIE0 { { RepairValue=0;|} } Status : discarded to avoid an additional block RepairSerialStructures which required significant content from ScanStructures block Assumes Re-timing logic (lock-up latch at the end of internal shift register) & access mechanism would be defined in waveform table.

CTL – Serial I/f (3) ScanStructures { … Other atpg scan chains } ScanStructures “RepairChains” { ScanChain "rep_chain_2" { ScanLength ; ScanIn ; ScanOut ; ScanCells ‘rep_chain_2[0..N-1]’; ScanMasterClock "CLK" ; ScanEnable ; RepairResetSignal ; RepairResetSate " " ; } MemoryRepair { // one block summarizing all repair info of the corresponding memory RepairResource { // 1 RepairResource block per spare unit Type ; Width // width of the resource, defaulted to 1 AddressMap RowAddressRange [R..0] ColumnAddressRange [C..0] DataRange [D..0] EnableConnectivity { // Defines enable state of redundancy element { {RepairSignal= ; RepairValue= ; AssociatedSignal={ }} + } } DataConnectivity { // Defines data bit dependency \u2013 Primarily used for column repair { {RepairSignal= ; RepairValue= ; AssociatedSignal={ }} + } } AddressConnectivity { // Defines address dependency - Primarily used for row / IO repair { {RepairSignal= ; RepairValue= ; AssociatedSignal={ }} + } } Status :Active Re-uses ScanStructures block and introduces no new construct Re-defined to to map serial interface into the existing connectivity block proposal

CTL Redundancy – model (latest proposal) MemoryRepair { // one block summarizing all repair info of the corresponding memory RepairResource { // 1 RepairResource block per spare unit // Defines reparability with the redundancy element Type ; Width // width of the resource, defaulted to 1 AddressMap // defines the possible starting addresses of that element p, and q can take any value provided that // starting_add belong to Column/Row AddressRange RowAddressRange [R..0] // required if the spare unit has restriction on the rows to replace - refers to the logical address ColumnAddressRange [C..0] // required if the spare unit has restriction on columns to replace – refers to the logical address DataRange [D..0] // required if the spare unit has restriction on the data I/O to replace // Defines memory repair data // Generic Syntax : { {RepairSignal= ; RepairValue= ; AssociatedSignal={ }} + } // RepairSignal : Defines the memory signal that defines repair value for RepairPort // RepairValue : Defines a fixed repair value for RepairPort // AssociatedSignal : Defines the associated memory port – always used with RepairValue EnableConnectivity {// Defines enable state of redundancy element { {RepairSignal= ; RepairValue= ; AssociatedSignal={ }} + } } DataConnectivity { // Defines data bit dependency – Primarily used for column repair { {RepairSignal= ; RepairValue= ; AssociatedSignal={ }} + } } AddressConnectivity {// Defines address dependency - Primarily used for row / IO repair { {RepairSignal= ; RepairValue= ; AssociatedSignal={ }} + } } RepairResource {…} … PortMap { { RepairRessources { } // (Optional) specifies the list of available resources for that port. If not all resources are assumed DataMap { Data[n..0] = // Data [3:0] = DA[0:3]; } AddressMap { Address[m..0] = // Address [7:0] = AA [8:1]; } } // PortMap ScanStructures { … Other atpg scan chains } ScanStructures “RepairChains” { ScanChain "rep_chain_2" { ScanLength ; ScanIn ; ScanOut ; ScanCells ‘rep_chain_2[0..N-1]’; ScanMasterClock "CLK" ; ScanEnable ; RepairResetSignal ; RepairResetSate " " ; } } // MemoryRepair