AR# 4120

Orcad Express: ROM outputs remain low in functional simulation

Description

Keywords: Orcad, simulation, functional, ROM

Urgency: Standard

General Description: When trying to perform a functional simulation of a
Xilinx design containing ROMs, the ROM outputs remain low, regardless
of the address accessed.

Solution

In Simulate v6.0, the Convert XNF to VHDL command on the Tools menu
ignores all part attributes such as ROM initialization. Xilinx ROMs are
initialized in the schematic by the OPTIONS_1 property as INIT=<value>.
As a workaround when using ROMs in a Xilinx design, translate the .XNF
files with the Timing Simulation option selected.

AR# 4120
Date 10/06/2008
Status Archive
Type General Article