6.42
IDT71V3556, IDT71V3558, 128K x 36, 256K x 18, 3.3V Synchronous SRAMS with
ZBT
™™
™™
™ Feature, 3.3V I/O, Burst Counter, and Pipelined Outputs Commercial and Industrial Temperature Ranges
23
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.
IDT Device ID (27:12) 0x208, 0x20A Defines IDT part number 71V3556SA and 71V3558SA, respectively.
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.
I5281 tbl 02
JTAG Identification Register Definitions (SA Version only)
Instruction Description OPCODE
EXTEST
Forces contents of the boundary scan cells onto the device outputs
(1 )
.
Places the boundary scan register (BSR) between TDI and TDO.
0000
SAMPLE/PRELOAD
Places the boundary scan register (BSR) between TDI and TDO.
SAMPLE allows data from device inputs
(2 )
and outputs
(1)
to be captured
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 output 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 bypass register (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 mandated 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
I5281 tbl 04
Available JTAG Instructions
