AR# 7995: 4.1i 4000XL MAP - "ERROR:OldMap:256 - Clock buffer BUFG symbol "..." cannot be converted to a BUFGLS due to location constraints."
AR# 7995
4.1i 4000XL MAP - "ERROR:OldMap:256 - Clock buffer BUFG symbol "..." cannot be converted to a BUFGLS due to location constraints."
描述
Keywords: OldMap 256, BUFGLS, UCF
Urgency: Standard
General Description: When I use pin LOC constraints on global clocks, the MAP report displays:
ERROR:OldMap:256 - Clock buffer BUFG symbol "..." cannot be converted to a BUFGLS due to location constraints.
解决方案
To work around this problem, LOC the clock buffer instead of using a pin LOC constraint.
For example:
INST "bufg_instance" LOC = "BUFGLS_SSW";
Clock buffers' LOCs are based on compass directions (SSW, NNW, NNE, etc.)