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AR# 4072

M1.4: WARNING:x4edr:21 - Blockcheck: CLB "frfi3_alism_fiCtr_upDown" is configured to use the G LUT as RAM, but the D1 and WE lines use the same pin, which will likely cause a D->WE setup violation.

Description

Keywords: Blockcheck, ram, we, d1, configure

Urgency : Hot

General Description:
Map give the following warning:
WARNING:x4edr:21 - Blockcheck: CLB "frfi3_alism_fiCtr_upDown" is configured to
use the G LUT as RAM, but the D1 and WE lines use the same pin, which will
likely cause a D->WE setup violation.


Solution

This is an incorrect warning. The SR mux is driving WE. The
same signal drives the H-LUT thru the H1 mux. Because the H1
mux also drives D1, drc warns about the setup violation.
The drc check doesn't realize that the D1 pin is going to the
H1 input of the HLUT not the D1 input of the RAM MODE block.
This is an incorrect warning because the DPRAM configuration
does not use D1.

This has been fixed in M1.5.

For now, the workaround is to use -d option in bitgen to
ignore the DRC error checking.
AR# 4072
Date Created 06/16/1998
Last Updated 05/18/1999
Status Archive
Type General Article