I am a novice. I have two clone V soc boards, and I generated some video data on the FPGA side of one of them and sent it to the HPS side through the H2F AXI bus. I want to send it to the second board through Ethernet. Before doing so, I used signalTap simulation to observe whether the HPS side can correctly read the data in the FIFO, but it seems to differ significantly from the written data. Can someone help me? Any help will be greatly appreciated.
Thank you in advance.
/* Code for reading data on the HPS side */
#include <stdio.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <stdint.h>
#include <unistd.h>
#define HW_REGS_BASE (0xC0000000)
#define HW_REGS_SPAN (0x04000000)
#define ALT_H2F_OFST (0xFF500000)
#define HW_REGS_MASK (HW_REGS_SPAN - 1)
#define LED_PIO_OFFSET (0x00000408)
int main()
{
int fd;
void *h2f_axi_base;
void *led_pio_addr;
fd = open("/dev/mem", O_RDWR | O_SYNC);
if (fd == -1) {
perror("could not open /dev/mem\n");
return 1;
}
h2f_axi_base = mmap(NULL, HW_REGS_SPAN, PROT_READ | PROT_WRITE, MAP_SHARED, fd, HW_REGS_BASE);
if (h2f_axi_base == MAP_FAILED) {
perror("could not mirror the H2F AXI address\n");
close(fd);
return 1;
}
led_pio_addr = h2f_axi_base + ( ( unsigned long ) (ALT_H2F_OFST + LED_PIO_OFFSET) & (unsigned long ) (HW_REGS_MASK) );
while (1) {
// read data
uint32_t data = *((volatile uint32_t *)led_pio_addr);
}
munmap(h2f_axi_base, HW_REGS_SPAN);
close(fd);
return 0;
}
Link Copied
I changed the FIFO to a dual port FIFO, and then used the same code to read the data in the FIFO. Everything looked normal. But when I added the function to send data, the reading of the data seemed to run counter to the correct result.
FIFO has a depth of 2048 and a width of 32. 
/* code for sending data */
#include <stdio.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>
#define HW_REGS_BASE (0xC0000000)
#define HW_REGS_SPAN (0x04000000)
#define ALT_H2F_OFST (0xFF500000)
#define HW_REGS_MASK (HW_REGS_SPAN - 1)
#define LED_PIO_OFFSET (0x00000408)
#define DEST_IP_ADDR "192.168.0.11"
#define DEST_PORT 1234
int main()
{
int fd;
void *h2f_axi_base;
void *led_pio_addr;
int sock;
struct sockaddr_in dest_addr;
fd = open("/dev/mem", O_RDWR | O_SYNC);
if (fd == -1) {
perror("could not open /dev/mem\n");
return 1;
}
h2f_axi_base = mmap(NULL, HW_REGS_SPAN, PROT_READ | PROT_WRITE, MAP_SHARED, fd, HW_REGS_BASE);
if (h2f_axi_base == MAP_FAILED) {
perror("could not mirror the H2F AXI address\n");
close(fd);
return 1;
}
led_pio_addr = h2f_axi_base + ((unsigned long)(ALT_H2F_OFST + LED_PIO_OFFSET) & (unsigned long)(HW_REGS_MASK));
sock = socket(AF_INET, SOCK_DGRAM, 0);
if (sock == -1) {
perror("socket creation failed\n");
munmap(h2f_axi_base, HW_REGS_SPAN);
close(fd);
return 1;
}
memset(&dest_addr, 0, sizeof(dest_addr));
dest_addr.sin_family = AF_INET;
dest_addr.sin_port = htons(DEST_PORT);
if (inet_pton(AF_INET, DEST_IP_ADDR, &(dest_addr.sin_addr)) <= 0) {
perror("inet_pton failed\n");
munmap(h2f_axi_base, HW_REGS_SPAN);
close(sock);
close(fd);
return 1;
}
while (1) {
uint32_t data = *((volatile uint32_t *)led_pio_addr);
if (sendto(sock, &data, sizeof(data), 0, (struct sockaddr *)&dest_addr, sizeof(dest_addr)) == -1) {
perror("sendto failed\n");
break;
}
}
close(sock);
munmap(h2f_axi_base, HW_REGS_SPAN);
close(fd);
return 0;
}
