da_dma_cycle.c

rt 7520采集卡 linux驱动源代码

/*
	FILE NAME: da_dma_cycle.c

	FILE DESCRIPTION:

		D/A conversion with fixed waveform generation.

		Waveform generation data is copied via DMA from buffer of up to
		64 kilobytes in size.  Samples are loaded directly into the
		DAC1 and DAC2 FIFO.

		This program is similar to da_dma but here DMA buffers are not
		updated once they are loaded.  Therefore, the control buffer is
		is not used.

	PROJECT NAME: Linux DM7520 Driver, Library, and Example Programs

	PROJECT VERSION: (Defined in README.TXT)

	Copyright 2004 RTD Embedded Technologies, Inc.  All Rights Reserved.
*/

#include <stdio.h>	//printf
#include <stdlib.h>	//exit
#include <errno.h>	//errno
#include <slang/slang.h>	//for anykey
#include "dm7520_library.h"


#define DABUFFERSIZE	(12288) // number od samples of waveform generator
int16_t *dabuffer1;	//pointer to the wave form buffer 1
int16_t *dabuffer2;	//pointer to the wave form buffer 2

// load the sqare wave to the buffer
void setBufSq(int16_t *buffer) {
	int i;
	int sample;
     for (i=0; i<DABUFFERSIZE/2;i++){
	 	sample=2047;
	 	buffer[i]=sample<<3;
     }
     for (i=DABUFFERSIZE/2;i<DABUFFERSIZE;i++) {
	 	sample = -2047;
	 	buffer[i]=sample<<3;
     }
}

// load the ramp wave to the buffer
void setBufRamp(int16_t *buffer) {
	int i;
	int sample;
     for (i=0; i<DABUFFERSIZE;i++){
	sample=	2047-(int)(4095.*i/DABUFFERSIZE);
      	buffer[i]=sample<<3;
     }
}

// wait for any key to be pressed

int anykey(void) {
    int x;
    SLang_init_tty(-1, 1, 1);
    x = SLang_getkey();
    SLang_reset_tty();    
    return x;
}

//=====================================================================
int main(int argc, char * argv[])
{
 FILE * infile;
 int ret;	// return code
 int devno;	// device handler


 if (argc<2) {fprintf(stderr,"Usage: %s <device>\n",argv[0]);exit(1);}

 if (NULL==(infile=fopen(argv[1],"r+"))) //open device.
   {
    fprintf(stderr,"Cannot open file, errno=%d\n",errno);
    perror("Error is");
    exit(2);
   }

   devno = fileno(infile);		// get device handler
 	InitBoard7520(devno);		//Initialize the device

DACClockFreeRun7520(devno, 1);	//set to start/stop mode
DACClockStopSelect7520 (devno, 7);	//Software D/A clock stop

//Set DMA to DA1 and obtain the buffer for wave form 1
    ret = setDA_DMA7520(devno, DM7520_WRITE_DA1,0, &dabuffer1, DABUFFERSIZE*2); // size in bytes, not samples
    if (ret) {
		printf("setDA1=%X\n", ret);
		goto label1;
    }

//Set DMA to DA2 and obtain the buffer for wave form 2
    ret = setDA_DMA7520(devno, DM7520_WRITE_DA2, 1, &dabuffer2, DABUFFERSIZE*2); // size in bytes, not samples
    if (ret) {
		printf("setDA2=%X\n", ret);
		goto label1;
    }

// Initialize the buffers
    setBufSq(dabuffer1);
    setBufRamp(dabuffer2);

// load the buffers to the FIFO
    setWriteBuffer7520(devno, DM7520_WRITE_DA1,0,DABUFFERSIZE*2); // size in bytes, not samples
    setWriteBuffer7520(devno, DM7520_WRITE_DA2,1,DABUFFERSIZE*2); // size in bytes, not samples

DACClockStartSelect7520 (devno, 7); //Software D/A clock start

if (SetupDAC7520(devno,DM7520_WRITE_DA1,AOUT_BIP5,DAC_CYCLE_SINGLE,DAC_START_DAC_CLK)) goto label1; // set up DAC1
if (SetupDAC7520(devno,DM7520_WRITE_DA2,AOUT_BIP5,DAC_CYCLE_SINGLE,DAC_START_DAC_CLK))goto label1; //set up DAC2


SetDACRate7520(devno, 100000);
DACClockStop7520(devno);	//need to have it here because of the bug in D/A clock
/*

   printf("Press any key to start conversion\n");
   anykey();
*/
   DACClockStart7520(devno);
 /*
   printf("\nCONVERSION STARTED\n\nPress any key to stop conversion\n");
   anykey();
   DACClockStop7520(devno);
*/
printf("press any key to stop conversion\n");
anykey();
//DACClockStop7520 (devno);	//Software D/A clock start

label1:


 ret = UnSetDMAMode7520(devno, 1);	// unset DMA1
// if (ret)
    printf("dma1 unset with code=%X\n", ret);

 ret = UnSetDMAMode7520(devno, 0);	// unset DMA0
// if (ret)
    printf("dma0 unset with code=%X\n", ret);


 fclose(infile);	// close device
 return(0);
}