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AR# 2069

QuickSim II: Output of XBLOX BUS_IFxx component is X

Description

Keywords: fncsim8, xblxgs, xblox, bus_if, unknown

Urgency: Standard

General description:

In a functional simulation in QuicksimII of a design that contains XBLOX
components, the outputs of BUS_IF (bus interface) symbols, such as
BUS_IF16, are X (unknown) even thoough the input is a valid logic value.

Solution

This is caused when the bounded side of the BUS_IFxx component is driven by
an XBLOX INPUTS symbol with a BOUNDS=0:0 attribute applied to it.

To fix this remove the BOUNDS and ENCODING attributes from the INPUTS
instance. If the INPUTS symbol is connected to a single NET, then
XBLXGS/XBLOX will infer a single bit width, and thus the BOUNDS attribute is
not necessary.
AR# 2069
Date Created 08/31/2007
Last Updated 10/06/2008
Status Archive
Type General Article