Answers Database
Bitgen 1.2: BUFGP sourced from internal logic may produce incorrect bitfile.
Record #2520
Product Family: Software
Product Line: FPGA Implementation
Product Part: bitgen
Product Version: 1.2.
Problem Title:
Bitgen 1.2: BUFGP sourced from internal logic may produce incorrect bitfile.
Problem Description:
Urgency: Hot
If you have the following arrangement for a 4000E:
logic------>BUFGP------->logic
where the BUFGP is sourced from internal logic instead of
a pin, Bitgen 1.2.11 may produce a .bit file where the BUFGP does not pass the input signal correctl
y.
Solution 1:
The following arrangement should work:
logic------->OBUF----x------->BUFGP------>logic
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IOPAD
Note that this is logically the same as the above; this is how
a BUFGP is actually implemented in a 4000E device when it
is sourced by internal logic.
This should be corrected for the M1.3 release ( you should be
able to use the more concise logic-->bufgp-->logic
arrangement).
End of Record #2520 - Last Modified: 07/10/97 11:22 |
