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.
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.
解决方案
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.