DFT在UPF之后需要用到带retention功能的scan dff,但是遇到问题:
Warnning:Model ‘RETN_SDSNV2_7TH40' during shift trace of scan_in fanned out to 1 paths
with only one latch and no DFFs in each scan path
This model will not be available for scan replacement or stitching in tessent shell flows.
推测是因为foundry提供的atpg model里用到两个latch对该cell建模,而不是用一个dff(写法上用两个
model udp_latch而不是一个model udp_dff)。导致Tessent不能将其识别为dff,请问该如何解决?