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AR# 23599

LogiCORE Multiplier v8.0 - How do I dynamically control the sign of my A port input, or why can I no longer use the a_signed input to control the sign of my A data input?

Description

How do I dynamically control the sign of my A port input, or why can I no longer use the a_signed input to control the sign of my A data input?

Solution

This information has been added to the Multiplier v9.0 data sheet, scheduled to be released in July 2006.  

 

If this functionality is required, it can be implemented externally to the core with some simple RTL code, as shown: 

 

VHDL example: 

-- when a_sign is '0', a_data will be zero-extended and when a_sign is '1', a_data will be sign-extended 

a_msb <= a_sign AND a_data(a'high);  

a_core <= a_msb & a_data(a'high-1 downto a'low);

AR# 23599
Date Created 09/04/2007
Last Updated 05/20/2014
Status Archive
Type General Article