2. Support
  3. AR# 5229: LogiCORE PCI - How do the REQ#/GNT#/RST# lines in the LogiCORE interface act?
  4. AR# 52292: LogiCORE Mutliplier Adder v2.0 - Why are the results incorrect when the input for an unsigned A input is less than or equal to 18, and a signed B input is greater than 18?

AR# 52292

LogiCORE Mutliplier Adder v2.0 - Why are the results incorrect when the input for an unsigned A input is less than or equal to 18, and a signed B input is greater than 18?

Description

Why are the results incorrect when the input for an unsigned A input is less than or equal to 18, and a signed B input is greater than 18?

For example:

  • A = Unsigned <= 18-bits (i.e. 17-bits)
  • B = Signed > 18-bits (i.e. 25-bits)

Solution

This is a known issue in the LogiCORE Multiplier Adder v2.0 in ISE 14.2 and earlier, or Vivado 2012.2 Design Suites.

This issue has been resolved in the LogiCORE Multiplier Adder v2.0 in ISE 14.3 and later and Vivado 2012.3 and later.
 
  • New users must either generate the core using ISE 14.3 or later or Vivado 2012.3 or later.
  • Existing users must regenerate their core using ISE 14.3 or later or Vivado 2012.3 or later.
Please see (Xilinx Answer 32141) for a detailed list of LogiCORE Multiply Adder Release Notes and Known Issues.

Linked Answer Records

Master Answer Records

Answer Number Answer Title Version Found Version Resolved
32141 LogiCORE Multiply Adder (MADD) - Release Notes and Known Issues N/A N/A
AR# 52292
Date 08/19/2014
Status Active
Type General Article
IP