AR# 2274: M1 MAP: Designs which fit a target XC4000/E/L device in XACT may not fit when mapped with the M1 Mapper due to register ordering
AR# 2274
M1 MAP: Designs which fit a target XC4000/E/L device in XACT may not fit when mapped with the M1 Mapper due to register ordering
Description
Keywords: fit overmap register ordering 4000 -r utilization
Urgency: standard
General Description:
Reference Number: 16695 Some designs which fit a specific XC4000/E/L device in XACT may not fit the same device when mapped with the M1 Mapper. One possible reason for this may be the fact that the M1 Mapper turns on register ordering by default. In designs containing registers, this may over-constrain the Mapper in such a way that it no longer has sufficient flexibility to achieve the optimal packing density for the design
Solution
If the reason for the higher resource utilization is due to register ordering, you can easily get around this by reprocessing your design through Map with register ordering disabled by specifying the -r option: