rp-test/axi_gen.c

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

#include "rp.h"
#include "rp_asg_axi.h"

// g++ axi_gen.c -std=c++20 -Wall  -I/opt/redpitaya/include -L/opt/redpitaya/lib -static -lrp-hw-can -lrp -lrp-hw-calib -lrp-hw-profiles -lrp-gpio -lrp-i2c -lrp-hw -lm -lstdc++ -lpthread -li2c -lsocketcan -o axi_gen

int main(int argc, char **argv) {

    // Select channel
    rp_channel_t channel = RP_CH_1;

    if(argc < 3)
    {
    	fprintf(stderr, "Invalid args!");
	return -1;
    }

    // Data size in samples (16 bit)

    uint32_t bufferSize = 4096;
    uint32_t freq = 3000000;

    if(argv[0] != nullptr)
    {
    	bufferSize = atoi(argv[1]);    // Should be twice the actual number of samples
    }
    uint32_t dec_factor = 1;
    uint32_t num_buffers = 1;
    if(argv[1] != nullptr)
    {
    	freq = atoi(argv[2]);
    }
    uint32_t ncyc = 1;
    uint32_t nor = 1;
    uint32_t period = 100;

    // Start addresses of buffers must be multiple of 4096 (DDR page size)
    uint32_t min_addr_diff = 4096;

    // Initialize the interface
    if (rp_Init() != RP_OK) {
        fprintf(stderr, "Rp api init failed!\n");
        return 1;
    }

    // Reset generator
    rp_GenReset();

    /* Setting up the Deep Memory Generation (DMG) */
    uint32_t dac_axi_start, dac_axi_size;

    // Get the reserved memory region start and size
    if (rp_AcqAxiGetMemoryRegion(&dac_axi_start, &dac_axi_size) != RP_OK) {
        fprintf(stderr, "Error get memory!\n");
        return 1;
    }

    // Lower the buffer size to the available memory size (if needed)
    uint32_t dmg_min_size = (uint32_t) (ceil((float) bufferSize / (float) min_addr_diff) * (float) min_addr_diff * (float) num_buffers);
    printf("Buffer size: %d\n", bufferSize);
    printf("Minimum size: %d\n", dmg_min_size);

    if (dmg_min_size > dac_axi_size) {
        printf("Buffer size is too large, reducing to available memory size\n");
        bufferSize = dac_axi_size / num_buffers;
        printf("Buffer size reduced to %d\n", bufferSize);
    }

    // Calculate the start address
    uint32_t gen1_start_addr = dac_axi_start;

    // Reserve memory for the generator
    printf("Reserved memory for OUT1 Start: %x Size: %x End: %x\n", gen1_start_addr, bufferSize, gen1_start_addr + bufferSize);

    if (rp_GenAxiReserveMemory(channel, gen1_start_addr, gen1_start_addr + bufferSize) != RP_OK) {
        fprintf(stderr, "Error setting address for DMG mode for OUT1\n");
        return 1;
    }

    // Set decimation factor
    if (rp_GenAxiSetDecimationFactor(channel, dec_factor) != RP_OK) {
        fprintf(stderr, "Error setting decimation for generator OUT1\n");
        return 1;
    }

    // Enable DMG mode
    if (rp_GenAxiSetEnable(channel, true) != RP_OK) {
        fprintf(stderr, "Error enable axi mode for OUT1\n");
        return 1;
    }

    // Define output waveform for both channels
    bufferSize /= 2;                // Samples are float32 which is 4 bytes, int16 is 2 bytes


    float *t = (float *)malloc(bufferSize * sizeof(float));
    float *x = (float *)malloc(bufferSize * sizeof(float));

    for (uint32_t i = 1; i < bufferSize; i++) {
        t[i] = t[i-1] + 0.000000008f;
    }

    for (uint32_t i = 0; i < bufferSize; ++i) {
	// x[i] = sin(t[i] * freq * 2 * M_PI) * ((1.0f * (bufferSize - i)) / bufferSize);
    	if(i > 512 && i < 3576)
	{
	    x[i] = 1.0f;
	}
	else
	{
	    x[i] = 0.0f;
	}
    }

    // Configure calibration and offset
    rp_GenSetAmplitudeAndOffsetOrigin(channel);

    // Set burst parameters
    rp_GenMode(channel, RP_GEN_MODE_BURST);
    rp_GenBurstCount(channel, ncyc);
    rp_GenBurstRepetitions(channel, nor);
    rp_GenBurstPeriod(channel, period);
    rp_GenAxiWriteWaveform(channel, x, bufferSize);

    rp_GenOutEnable(channel);
    rp_GenTriggerOnly(channel);

    // Release resources
    free(t);
    free(x);

    rp_Release();

    return 0;
}