AR# 1167

XABEL: AHDL2X will hang at "processing equations..." with wide buses.

Description

In processing an xabel design, you might see a probelm like this:
{jamesm@nuke-8}ahdl2x ndiff
AHDL2X ABEL-HDL Processor
Xilinx-ABEL 5.12 Copyright 1992-1994 Data I/O Corp. All Rights Reserved.

Module: 'ndiff'

Processing equations.....

and it never makes further progress. This can be due to a
limitation of XABEL in handling larger width counters, adders,
comparators, etc.

Solution

The @CARRY directive allows the reduction of the amount of
logic required for processing large arithmetic functions, by specifying the maximum bit width.

Xabel can handle up to 8 bits without problems. To force xabel
to break a design up into 8 bit sections use this directive:

@CARRY 8;

under the EQUATIONS keyword.

This will force XABEL to generate 8-bit functions only.
AR# 1167
Date 01/15/2003
Status Archive
Type General Article