Answers Database
XSI Libraries 2.1i: Bidirectional I/O has extra inversion inferred (IOBUF_N)
Record #7470
Product Family: Software
Product Line: Synopsys
Product Part: xsi-libs
Product Version: 2.1i
Problem Title:
XSI Libraries 2.1i: Bidirectional I/O has extra inversion inferred (IOBUF_N)
Problem Description:
Urgency: Hot
General Description:
When creating a bidirectional I/O, Synopsys Design Compiler or FPGA Compiler will
use an IOBUF_N component. With Xilinx version 1.5i or earlier, this represented a
standard bidirectional I/O with no inversions, but that functionality changed with 2.1i,
as inversion was now introduced on the input buffer.
This results in a functionally incorrect netlist.
Solution 1:
This problem is fixed in the latest 2.1i Service Pack available at:
http://support.xilinx.com/support/techsup/sw_updates/
End of Record #7470 - Last Modified: 10/15/99 16:48 |
