23

IDT70V659/58/57S

High-Speed 3.3V 128/64/32K x 36 Asynchronous Dual-Port Static RAM

Industrial and Commercial Temperature Ranges

Identification Register Definitions

Instruction Field

Value

Description

Revision Number (31:28)

0x0

Reserved for version number

IDT Device ID (27:12)

Defines IDT part number

IDT JEDEC ID (11:1)

0x33

Allows unique identification of device vendor as IDT

ID Register Indicator Bit (Bit 0)

1

Indicates the presence of an ID register

4869 tbl 20

Scan Register Sizes

Register Name

Bit Size

Instruction (IR)

4

Bypass (BYR)

1

Identification (IDR)

32

Boundary Scan (BSR)

Note (3)

4869 tbl 21

System Interface Parameters

Instruction

Code

Description

EXTEST

0000

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

BYPASS

1111

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

IDCODE

0010

Loads the ID register (IDR) with the vendor ID code and places the

register between TDI and TDO.

HIGHZ

0100

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

device output drivers to a High-Z state.

CLAMP

0011

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

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

SAMPLE/PRELOAD

0001

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.

RESERVED

All other codes

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

identified above.

4869 tbl 22

NOTES:

1. Device outputs = All device outputs except TDO.

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

3. The Boundary Scan Descriptive Language (BSDL) file for this device is available on the IDT website (www.idt.com), or by contacting your local

IDT sales representative.

NOTE:

1. Device ID for IDT70V658 is 0x30B. Device ID for IDT70V657 is 0x323.