格雷码&&独热码生成

//自然二进制数转格雷码
module bin2gray #(
    parameter width = 4 //定义数据的位宽参数为4
    )(
    input   [width - 1 : 0]  bin,
    output  [width - 1 : 0]  gray
    );
//二进制数逻辑右移与自身进行异或逻辑运算
assign gray = (bin >> 1) ^ bin;
endmodule

//格雷码转自然二进制数
module gray2bin #(
    parameter width = 4 //定义数据的位宽参数为4
    )(
    input   [width - 1 : 0]  gray,
    output  [width - 1 : 0]  bin
);
//利用generate...for逐位循环输出最低位至次高位二进制数
genvar i;
generate
    for(i = width - 2; i >= 0; i = i - 1) begin: gray_2_bin
        assign bin[i] = bin[i + 1] ^ gray[i];  //格雷码与二进制数前一位进行异或逻辑运算
    end
endgenerate
//二进制数最高位为格雷码最高位
assign bin[width - 1] = gray[width - 1];
endmodule

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define ONEHOT_MODE  (1)
#define GRAY_MODE    (2)
unsigned int binary2gray(unsigned int  n ){
  return n ^ ( n >> 1 );
}
unsigned int getbitnum(unsigned int number){
  unsigned int num = 0;
  while(number){
    number = number >> 1;
    num ++;
  }
  return num;
}
void show_onehot(int index, int total_num){
  for( int i=0;i<total_num-1-index;i++){
    printf("0");
  }
  printf("1");
  for(int i = 0 ;i<index;i++){
    printf("0");
  }
  printf("\r\n");
}
void show_gray(int num,unsigned int total_num){
  unsigned int num_bit = getbitnum((unsigned int) num);
  for( unsigned int i=0;i<total_num-num_bit;i++){
    printf("0");
  }
  int rl = num_bit -1;
  for(int i=0;i<num_bit;i++){
    printf("%d",(num>>rl ) & 0x01);
    rl--;
  }
  
  printf("\r\n");
}
void help_info(){
  printf("\r\nCreate OneHot && Gray Code !\r\n");
  printf("usage:\r\n");
  printf("  ogcode [-g] num \r\n");
  printf("  <-- both start_range and end_range should >= 0 -->\r\n");
  printf("--> -g : gray mode, default onehot mode\r\n");
  printf("--> -h/--help : help info\r\n");
}
int main(int argc ,char * argv[]){
  int  number_num;
  char work_mode ;
  
  if( argc < 2 ){
    help_info();
    return -1;
  } else if( !strcmp(argv[1],"-h") || !strcmp(argv[1],"--help") ){
    help_info();
    return -1;
  }else if( argc == 2 ){
    number_num = atoi(argv[1]);
    work_mode = ONEHOT_MODE;
  }else if( argc == 3){
    if( strcmp(argv[1],"-g") ){
      help_info();
      return -1;
    }
    number_num =atoi(argv[2]);
    work_mode = GRAY_MODE;
  }else{
    help_info();
    return -1;
  }
  if( number_num <= 0 ){
    help_info();
    return -1;
  }
  
  /************************ main function ******************************/
  if( work_mode == ONEHOT_MODE){
    printf("The num bit is %u\r\n",number_num);
    for( int i=0;i<number_num;i++){
      show_onehot(i,number_num);
    }
  }else if( work_mode == GRAY_MODE ){
    unsigned int num_bit = getbitnum((unsigned int)(number_num));
    printf("The num bit is %u\r\n",num_bit);
    for( int i=0;i<number_num;i++){
      show_gray(binary2gray((unsigned int)i),num_bit);
    }
  }else {
    printf("unknown error \r\n");
  }
  return 0;
}