Cypress CY7C1248V18 Manuel D’Utilisation
CY7C1246V18, CY7C1257V18
CY7C1248V18, CY7C1250V18
CY7C1248V18, CY7C1250V18
Document Number: 001-06348 Rev. *D
Page 17 of 27
Identification Register Definitions
Instruction
Field
Value
Description
CY7C1246V18
CY7C1257V18
CY7C1248V18
CY7C1250V18
Revision
Number (31:29)
Number (31:29)
000
000
000
000
Version number.
Cypress Device
ID (28:12)
ID (28:12)
11010111100000111
11010111100001111
11010111100010111
11010111100100111 Defines the type
of SRAM.
Cypress JEDEC
ID (11:1)
ID (11:1)
00000110100
00000110100
00000110100
00000110100
Enables unique
identification of
SRAM vendor.
identification of
SRAM vendor.
ID Register
Presence (0)
Presence (0)
1
1
1
1
Indicates the
presence of an
ID register.
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.
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.
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.
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.
SRAM operation.