Answers Database
 
 
 M1.5 Map - Map fatal error when IFDX output is fed back to OFDTX loc'd to same pad. 
 
 Record #5075
Problem Title: 
M1.5 Map - Map fatal error when IFDX output is fed back to OFDTX loc'd to same pad.  
 
 
Problem Description: 
FATAL_ERROR:x4kma:x4kmap.c:3087:1.151 - 0 flip-flop basic 
elements found, at least 1 expected for CLB amcc_DQ_outff<31>. 
 
The design has an IBUF, IFDX and OFDTX all LOC'd to P98. 
The error is related to the fact that the IFDX ouput drives 
the OFDTX input (see net configreg_1<31>). If I put a buffer 
between this net and the OFDTX input, the design maps okay. 
 
 
 
Solution 1: 
 
 
The problem occurs when the STARTUP is connected to a pin of the OFDTX.  The work-around is to inser
t a buffer between the STARTUP and the OFDTX. 
 
 
 
 
Solution 2: 
 
This error has also been known to ocurr on designs with GSR nets from the STARTUP component driving
the T pin of OFDTX symbols. The work around is to place a buffer 
between the GSR net and the T pin. 
 
 
 
 End of Record #5075 - Last Modified: 05/18/99 13:49  |