The goal

This is very slow attempt to implement SDR from scratch on Zynq 7020. I have 65Msample 8bit ADC and Zynq board. The goal is to gather the signal from ADC, extract IQ signals and send to PC

structure

• dma_sg.h/dma_sg.c - this is pure implementation of scatter gather dma S2MM mode. - works fine so far
• tcp* - this is for tcp. still very raw. Achieved speed is 58.7Mbytes/sec. It is equals to 60 000 000 bytes per second which is desired rate for ADC (30Mhz 16Bit 8bit for I and 8Bit for Q)

platform settings

lwip changes parameters

• lwip220_dhcp = true
• lwip220_memp_n_pbuf = 500
• lwip220_memp_n_tcp_seg = 1024
• lwip220_pbuf_pool_size = 512
• lwip220_tcp_snd_buf = 65535
• lwip220_tcp_wnd = 65535
• lwip220_temac_tcp_ip_rx_checksum_offload = true
• lwip220_temac_tcp_ip_tx_checksum_offload = true

modules enabled:

• xil timer
• lwip

hardware

I have one DMA in sg mode

How I'm tesing

For now instead of real ADC I added counter with 16bit width Values from the counter I'm sending to AXI FIFO with dual channel clock Counter clocked with 30MHz and all peripheral clocked with 100MHz for the moment On the receiving side I started simple validation

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>

int main() {
    uint16_t number;
    uint16_t prev_number = 0;
    // Continuously read and print unsigned 16-bit integers until EOF
    while (fread(&number, sizeof(uint16_t), 1, stdin) == 1) {
	if (number - prev_number != 1 && number != 0) {
		printf("error. diff is %u\n", number - prev_number);  // Print as unsigned integer
	}
	prev_number = number;
	//printf("%u\n", number);
    }

    // If we reach here, it's either EOF or a read error
    if (feof(stdin)) {
        // End of file reached
        return 0;
    } else {
        // Some error occurred
        fprintf(stderr, "Error: Could not read from input.\n");
        return 1;
    }
}