4、 Asyncfifo design using Verilog
module asyn_fifo(
input wclk ,
input rst_n ,
input wr_en ,
input [7 : 0] data_in ,
output full ,
input rclk ,
input rd_en ,
output reg [7:0] data_out ,
output empty
);
reg [7 : 0 ] mem[7 : 0] ;
wire [2:0] r_addr , w_addr ;
reg [3:0] binary_r_addr , binary_w_addr ;
wire [3:0] gray_r_addr , gray_w_addr ;
reg [3:0] gray_r_addr_reg , gray_w_addr_reg ;
assign gray_r_addr = ( binary_r_addr >> 1 ) ^ binary_r_addr;
assign gray_w_addr = ( binary_w_addr >> 1 ) ^ binary_w_addr;
assign r_addr = gray_r_addr[2:0] ;
assign w_addr = gray_w_addr[2:0] ;
always@(posedge rclk or negedge rst_n ) begin
if(~rst_n) begin
binary_r_addr <= 4'b0 ;
gray_w_addr_reg <= 4'b0 ;
data_out <= 8'b0 ;
end
else begin
gray_w_addr_reg <= gray_w_addr ;
if(rd_en == 1'b1 && empty == 1'b0) begin
data_out <= mem[r_addr] ;
binary_r_addr <= binary_r_addr + 1'b1 ;
end
end
end
always@(posedge wclk or negedge rst_n) begin
if(~rst_n) begin
binary_w_addr <= 4'b0 ;
gray_r_addr_reg <= 4'b0 ;
end
else begin
gray_r_addr_reg <= gray_r_addr ;
if(wr_en == 1'b1 && full == 1'b0 )begin
mem[w_addr] <= data_in ;
binary_w_addr <= binary_w_addr + 1'b1 ;
end
end
end
assign empty = (gray_r_addr == gray_w_addr_reg) ? 1:0 ;
assign full = ( (gray_w_addr[3] !== gray_r_addr_reg[3]) && (gray_w_addr[2] !== gray_r_addr_reg[2]) &&(gray_w_addr[1:0] == gray_r_addr_reg[1:0]) ) ? 1:0 ;
endmodule
module sequence_detect(
input clk,
input rst_n,
input [7:0] stringB_in,
input stringB_en ,
input stringB_over ,
output reg [4:0] location,
output reg out_valid
);
reg [4:0] location_reg_count;
always @ (posedge clk or negedge rst_n) begin
if(!rst_n)
location_reg_count <= 5'd0;
else if(stringB_en == 1'b1 && stringB_over == 1'b0) begin
location_reg_count <= location_reg_count+1;
end
end
reg [4:0] location_reg;
always @ (posedge clk or negedge rst_n) begin
if(!rst_n)
location_reg <= 0;
else if (stringB_en == 1'b1 && stringB_over == 1'b0 ) begin
if(stringB_in == "n" || stringB_in == "v" || stringB_in == "i" ||stringB_in == "d" || stringB_in == "a") begin
location_reg <= location_reg_count ;
end
else begin
location_reg <= location_reg ;
end
end
end
always @ (posedge clk or negedge rst_n) begin
if(!rst_n)
out_valid <= 0;
else if (stringB_over == 1'b1 ) begin
location <= location_reg ;
out_valid <= 1'b1;
end
else begin
location <= 0 ;
out_valid <= 1'b0;
end
end
endmodule
#include <stdio.h>
#include "malloc.h"
void NumSort(int *number, int numbersize);
int *intersection_numbers(int *number1, int numbersize1, int *number2, int numbersize2,int *intersection_size);
int *union_numbers(int *number1, int numbersize1, int *number2, int numbersize2, int *union_size);
void NumSort(int *number, int numbersize) {
int min, temp;
int i;
int j;
for (i = 0; i<numbersize - 1; i++) {
min = i;
for (j = i + 1; j<numbersize; j++) {
if (number[min]>number[j]) {
min = j;
}
}
if (min != i) {
temp = number[min];
number[min] = number[i];
number[i] = temp;
}
}
}
int *intersection_numbers(int *number1, int numbersize1, int *number2, int numbersize2,int *intersection_size) {
int temp, i, j;
int *result = (int *)malloc(numbersize1 * sizeof(int));
*intersection_size = 0;
NumSort(number1, numbersize1);
NumSort(number2, numbersize2);
temp = number1[numbersize1 - 1] + number2[numbersize2 - 1];
for (i = 0, j = 0; i<numbersize1&&j<numbersize2;) {
if (number1[i]>number2[j]) {
j++;
}
else if (number1[i]<number2[j]) {
i++;
}
else {
if (temp != number1[i]) {
result[(*intersection_size)++] = number1[i];
temp = number1[i];
}
i++;
j++;
}
}
return result;
}
int* union_numbers(int* number1, int numbersize1, int* number2, int numbersize2,int *union_size) {
int temp, i, j;
int *result = (int *)malloc((numbersize2 + numbersize1) * sizeof(int));
NumSort(number1, numbersize1);
NumSort(number2, numbersize2);
i = 0;
j = 0;
*union_size = 0;
temp = number1[numbersize1 - 1] + number2[numbersize2 - 1];
for (i = 0, j = 0; i<numbersize1 || j<numbersize2;) {
if (j != numbersize2 && number1[i]>number2[j]) {
result[(*union_size)++] = number2[j];
j++;
}
else if (i != numbersize1 && number1[i]<number2[j]) {
result[(*union_size)++] = number1[i];
i++;
}
else if (j == numbersize2 && number1[i]>number2[j]) {
result[(*union_size)++] = number1[i];
i++;
}
else if (i == numbersize1 && number1[i]<number2[j]) {
result[(*union_size)++] = number2[j];
j++;
}
else {
if (temp != number1[i]) {
result[(*union_size)++] = number1[i];
temp = number1[i];
}
i++;
j++;
}
}
return result;
}
int main(int argc, char *argv[])
{
int a[10] = { 1,2,3,4,5,6,7,8,9,10 };
int i;
int b[10] = { 2,4,6,8,10,12,14,16,18,20 };
int intersection_size = 0 ;
int union_size = 0 ;
int *p = intersection_numbers(&a[0], 10, &b[0], 10,&intersection_size);
printf("\n +++++ array a :\n");
for (i = 0; i<10; i++) {
printf(" %d\n", a[i]);
}
printf("\n +++++ array b :\n");
for (i = 0; i<10; i++) {
printf(" %d\n", b[i]);
}
printf("++++++ intersection of the array a && b\n");
for (i = 0; i<intersection_size;) {
printf(" %d\n", p[i]);
i++;
}
int *p1 = union_numbers(&a[0], 10, &b[0], 10, &union_size);
printf("++++++ union of the array a || b\n");
for (i = 0; i<union_size;) {
printf(" %d\n", p1[i]);
i++;
}
getchar();
}