Cypress CY7C1241V18, CY7C1243V18, CY7C1245V18, CY7C1256V18 CY7C1241V18, CY7C1256V18 CY7C1243V18, CY7C1245V18

CY7C1241V18, CY7C1256V18
CY7C1243V18, CY7C1245V18
Document Number: 001-06365 Rev. *D Page 18 of 28
Identification Register Definitions
Instruction
Field Value Description
CY7C1241V18 CY7C1256V18 CY7C1243V18 CY7C1245V18
Revision
Number (31:29) 000 000 000 000 Version number.
Cypress Device
ID (28:12) 11010010101000111 11010010101001111 11010010101010111 11010010101100111 Defines the type of SRAM.
Cypress JEDEC
ID (11:1) 00000110100 00000110100 00000110100 00000110100 Enables unique identification of
SRAM vendor.
ID Register
Presence (0) 1111Indicates the presence of an
ID register.
Scan Register Sizes
Register Name Bit Size
Instruction 3
Bypass 1
ID 32
Boundary Scan 109
Instruction Codes
Instruction Code Description
EXTEST 000 Captures the input/output ring contents.
IDCODE 001 Loads the ID register with the vendor ID code and places the register between
TDI and TDO. This operation does not affect SRAM operation.
SAMPLE Z 010 Captures the input/output contents. Places the boundary scan register between
TDI and TDO. Forces all SRAM output drivers to a High-Z state.
RESERVED 011 Do Not Use: This instruction is reserved for future use.
SAMPLE/PRELOAD 100 Captures the input/output ring contents. Places the boundary scan register
between TDI and TDO. Does not affect the SRAM operation.
RESERVED 101 Do Not Use: This instruction is reserved for future use.
RESERVED 110 Do Not Use: This instruction is reserved for future use.
BYPASS 111 Places the bypass register between TDI and TDO. This operation does not affect
SRAM operation.
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