GS8182D08BD-167I Datasheet, PDF (28/36 Pages) GSI Technology – 18Mb SigmaQuad-IITM Burst of 4 SRAM

GS8182D08/09/18/36BD-400/375/333/300/250/200/167
Typically, the Boundary Scan Register is loaded with the desired pattern of data with the SAMPLE/PRELOAD command.
Then the EXTEST command is used to output the Boundary Scan Register’s contents, in parallel, on the RAM’s data output
drivers on the falling edge of TCK when the controller is in the Update-IR state.
Alternately, the Boundary Scan Register may be loaded in parallel using the EXTEST command. When the EXTEST instruc-
tion is selected, the sate of all the RAM’s input and I/O pins, as well as the default values at Scan Register locations not asso-
ciated with a pin, are transferred in parallel into the Boundary Scan Register on the rising edge of TCK in the Capture-DR
state, the RAM’s output pins drive out the value of the Boundary Scan Register location with which each output pin is associ-
ated.
IDCODE
The IDCODE instruction causes the ID ROM to be loaded into the ID register when the controller is in Capture-DR mode and
places the ID register between the TDI and TDO pins in Shift-DR mode. The IDCODE instruction is the default instruction
loaded in at power up and any time the controller is placed in the Test-Logic-Reset state.
SAMPLE-Z
If the SAMPLE-Z instruction is loaded in the instruction register, all RAM outputs are forced to an inactive drive state (high-
Z) and the Boundary Scan Register is connected between TDI and TDO when the TAP controller is moved to the Shift-DR
state.
JTAG TAP Instruction Set Summary
Instruction Code
Description
EXTEST
000
Places the Boundary Scan Register between TDI and TDO.
IDCODE
001
Preloads ID Register and places it between TDI and TDO.
SAMPLE-Z
010
Captures I/O ring contents. Places the Boundary Scan Register between TDI and TDO.
Forces all RAM output drivers to High-Z.
GSI
011
GSI private instruction.
SAMPLE/PRELOAD 100
Captures I/O ring contents. Places the Boundary Scan Register between TDI and TDO.
GSI
101
GSI private instruction.
GSI
110
GSI private instruction.
BYPASS
111
Places Bypass Register between TDI and TDO.
Notes:
1. Instruction codes expressed in binary, MSB on left, LSB on right.
2. Default instruction automatically loaded at power-up and in test-logic-reset state.
Notes
1
1, 2
1
1
1
1
1
1
Rev: 1.03d 11/2011
28/36
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
© 2007, GSI Technology