Answers Database
JTAG - Do Update Latches and Data Registers get reset in Test Logic Reset State?
Record #2195
Product Family: Hardware
Product Line: 4000
Product Part: 4000
Problem Title:
JTAG - Do Update Latches and Data Registers get reset in Test Logic Reset State?
Problem Description:
Urgency: Standard
General Description:
What happens to the Update Latches and Data/Instruction Registers
of the boundary scan circuitry when the device enters the
Test-Logic-Reset state? Do they get set or reset?
Solution 1:
When the device enters the Test-Logic-Reset state, the BYPASS
instruction becomes the current instruction and hence the
Instruction register and the Update latches are SET (output
HIGH).
The 1-bit BYPASS register is selected by the BYPASS Instruction.
The user may shift out the data in this register by performing
the shift-DR instruction.
End of Record #2195 - Last Modified: 01/10/00 21:24 |
