Answers Database
JTAG - What is the state of the INIT pin during boundary scan configuration?
Record #143
Problem Title:
JTAG - What is the state of the INIT pin during boundary scan configuration?
Problem Description:
Urgency: Standard
General Description:
The state of the /INIT pin on a XC4000 family device and its derivatives
during configuration using Boundary Scan.
Solution 1:
In order to configure the XC4000, XC5200, and Spartan devices
using boundary scan, the /INIT pin should be held low until the
CONFIGURE instruction has been executed.
If INIT is not held low, the device may assume standard configuration, sample the mode lines,
and disable the JTAG Boundary scan architecture.
Additionally, momentary glitches on the INIT pin may cause the device to be
thrown out of boundary scan mode, or to give nonsensical scan
outputs.
End of Record #143 - Last Modified: 01/06/00 15:51 |
