AR# 38871: Virtex-5 - IDELAY - Why is the RST grounded in the .ncd when fixed tap-delay mode is used?
AR# 38871
Virtex-5 - IDELAY - Why is the RST grounded in the .ncd when fixed tap-delay mode is used?
Description
Why is the RST grounded in the .ncd when fixed tap-delay mode is used?
解决方案
The IDELAY's RST is used to reset the delay chain to a pre-programmed value. When fixed mode is used the delay value is set to a number specified by the IOBDELAY_VALUE and cannot be reset.