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AR# 61888

2014.2 Vivado HLS - Interface "ap_vld" cannot be inferred when there is float to ap_fixed conversion.

Description


I have an issue occurring in float to ap_fixed conversion.

The Signal "mysig" is synthesized as "ap_none", not "ap_vld", which is what I specified.

It can be reproduced with the following code:

#include <ap_fixed.h>
typedef ap_fixed<32, 32, AP_RND_CONV, AP_SAT> MYFIX_TYPE;
void f_0(volatile ap_int<32> * dest, float mysig)
{
#pragma HLS INTERFACE ap_vld port=mysig
MYFIX_TYPE mylocal;
mylocal = (MYFIX_TYPE)mysig;
(*dest) = ((ap_int<32>)(mylocal));
}

Solution

This is a known issue in the 2014.2 version of Vivado HLS.
 
It does not exist in Vivado 2013.4.
 
It is fixed in Vivado 2014.3.
AR# 61888
Date Created 08/31/2014
Last Updated 02/20/2015
Status Active
Type Known Issues
Tools
  • Vivado Design Suite - 2013.4