ASIC/FPGA Design and Verification Out Source Services

GHDL c interfaces and extensions random number generation.

1. Based on the example, I created a makefile and changed some of the source code to run in a standalone mode. I have also found this page to be helpful. This work may also interest you.


2. This c code generates random numbers for a VHDL test-bench. So far I did random numbers for VHDL benches in a very cumbersome way:
   Simili vhdl simulator test bench with uniform random.
   VHDL function, which generates random numbers.


3. I created a function that receives a seed, which it will use only once, and sample size and probability. The function then generates a number and returns boolean if in range.
   
   
4. //random generator for GHDL
   #include <stdio.h>
   #include <stdlib.h>
   #include <string.h>
   
   #include <sys/io.h>
   
   char srand_f = 1;
   
   int g_rand_c(int seed, int Pmax, int Prob) {
   
     int rnum;
   
     if(srand_f) {
       srand( (unsigned)seed);
       srand_f = 0;
     }
     rnum = rand() % Pmax;
     return rnum > Prob ? 1 : 0;
   
   }
   


5. --Part of the VHDL bench
   ...
   package pkg_g_rand is
     function g_rand (seed, Pmax, Prob: integer) return integer;
       attribute foreign of g_rand : function is "VHPIDIRECT g_rand_c";
   end pkg_g_rand;
   
   package body pkg_g_rand is
     function g_rand (seed, Pmax, Prob: integer) return integer is
     begin
       assert false report "VHPI" severity failure;
     end;
   end pkg_g_rand;
   ...
   


6. The code can be downloaded from: code