AS8C403625, AS8C401825, 128K x 36, 256K x 18, 3.3V Synchronous SRAMs with

3.3V I/O, Flow-Through Outputs, Burst Counter, Single Cycle Deselect

Commercial Temperature Range

NOTES:

1. Device outputs = All device outputs except TDO.

2. Device inputs = All device inputs except TDI, TMS, and

TRST.

Instruction Field

Value

Description

Revision Number (31:28)

0x2

Reserved for version number.

Device ID (27:12)

0x22C, 0x22E

Defines

AS8C403625/1825

JEDEC ID (11:1)

0x33

Allows unique identification of device vendor .

ID Register Indicator Bit (Bit 0)

1

Indicates the presence of an ID register.

I5280 tbl 02

JTAG Identification Register Definitions (SA Version only)

Instruction

Description

OPCODE

EXTEST

Places the boundary scan register (BSR) between TDI and TDO.

0000

SAMPLE/PRELOAD

Places the boundary scan register (BSR) between TDI and TDO.

in the boundary scan cells and shifted serially through TDO. PRELOAD

allows data to be input serially into the boundary scan cells via the TDI.

0001

DEVICE_ID

Loads the JTAG ID register (JIDR) with the vendor ID code and places

the register between TDI and TDO.

0010

HIGHZ

Places the bypass register (BYR) between TDI and TDO. Forces all

device o utput drivers to a High-Z state.

0011

RESERVED

Several combinations are reserved. Do not use codes other than those

identified for EXTEST, SAMPLE/PRELOAD, DEVICE_ID, HIGHZ, CLAMP,

VALIDATE and BYPASS instructions.

0100

RESERVED

0101

RESERVED

0110

RESERVED

0111

CLAMP

Uses BYR. Forces contents of the boundary scan cells onto the device

outputs. Places the byp ass registe r (BYR) between TDI and TDO.

1000

RESERVED

Same as above.

1001

RESERVED

1010

RESERVED

1011

RESERVED

1100

VALIDATE

Automatically loaded into the instruction register whenever the TAP

controller passes through the CAPTURE-IR state. The lower two bits '01'

are mand ated by the IEEE std. 1149.1 specification.

1101

RESERVED

Same as above.

1110

BYPASS

The BYPASS instruction is used to truncate the boundary scan register

as a single bit in length.

1111

I5280 tbl 04

Available JTAG Instructions