AR# 53519

Vivado 2012.x - How does Vivado Synthesis treat KEEP or DONT_TOUCH on a state machine register upon turning on FSM extraction?

Description

How does Vivado Synthesis treat KEEP or DONT_TOUCH on a state machine register when FSM extraction is turned on?

Solution

When FSM extraction is turned on and there is a KEEP or DONT_TOUCH attribute on the state machine register, Vivado Synthesis ignores the KEEP or DONT_TOUCH attribute.

To work around this issue, turn off FSM extraction to allow the KEEP or DONT_TOUCH to be used.

The issue is fixed in 2013.1 release of Vivado Synthesis.

AR# 53519
Date 06/21/2013
Status Active
Type Known Issues
Tools