AR# 8064


2.1i COREGEN: Outputs in Dynamic Constant Coefficient Multiplier Verilog model change asynchronously


Keywords: verilog, constant, coefficient, multiplier, latency

Urgency: standard

General Description:
The following problems may be seen with the Verilog model for the 4K Constant Coefficient
Multiplier core when simulating in Synopsys VCS or Verilog-XL:

1. There is no latency between the input transitions and output transitions--the output
changes immediately after a new input value is clocked in.
2. Race condition associated with transitioning of the output on a rising clock edge

The problems are similar to those found in the Virtex Dynamic Constant Coefficient Multiplier Verilog model
as described in (Xilinx Solution #8020). The symptoms show up in VCS and Verilog-XL.



Under investigation.


An alternative workaround is to generate a post-NGDBUILD simulation netlist for the
core in place of its behavioral model. Please refer to (Xilinx Solution #8065) for details on
how to do this.
AR# 8064
Date 08/01/2001
Status Archive
Type General Article
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