In-system Programming Clamp State

Allows you to specify the state that the pins take during in-system programming for used pins that do not have an in-system programming clamp state assignment. Unused pins and dedicated inputs must always be tri-stated for in-system programming. Used pins are tri-stated by default during in-system programming, which electrically isolates the device from other devices on the board. At times, however, in order to prevent system damage you may want to specify the logic level for used pins during in-system programming. The following settings are available:


I/O Pin State


The pins are tri-stated.


The pins drive VCCIO.


The pins drive GND.

Sample and Sustain

The pins drive the level captured during the SAMPLE/PRELOAD JTAG instruction.