AR# 6983

JTAG - What should I do with mode pins when I use JTAG configuration for an FPGA?

Description

General Description:

What should I do with mode pins during FPGA JTAG configuration?

Solution

For Spartan/XL or XC4000/E/XL/XV devices:

/INIT should be pulled low upon power up for JTAG configuration. With /INIT low, the values on the mode pins will not be considered,

and can therefore be left hanging.

For Virtex/E/II or Spartan-II devices:

Configuration through the boundary-scan port is always available, and it is independent of the mode selection. Selecting the boundary-scan mode simply turns off the other modes.

AR# 6983
Date 12/15/2012
Status Active
Type General Article