tms470r1a256_adc10_06.c

tmp470开发板的源程序

//******************************************************************************
//  Functional
//  TMS470 Demo - MibADC Buffered Sample with polling
//
//  Description; the MibADC is used in buffered mode.  20 samples are taken
//  in continuous mode from channel 9 and are placed in the group 1 FIFO.
//  20 samples are read and averaged.  The average is displayed on the LEDs
//  Software sets starts sample and conversion and polls for end of conversion.
//
//  Total sample and convert time = 12MHz/(8*((62+2)+11)) = 20KSPS
//  ACLK = SYSCLK = MCLK = ICLK = 12MHz
//  //*An external 12Mhz XTAL on OSCIN OSCOUT with proper load caps required*//	
//
//              TMS-FET470A256
//             -----------------
//         /|\|            OSCIN|-
//          | |                 | 12MHz
//          --|PLLDIS     OSCOUT|-
//            |                 |
//        >---|ADIN0         HET|---> 10 LEDs
//            |                 |
//
//  L.Westlund/J.Mangino
//  Texas Instruments, Inc
//  January 2005
//  Built with IAR Embedded Workbench Version: 3.20A
//******************************************************************************

#include <intrinsic.h>
#include "iotms470r1a256.h"
#include "tms470r1a256_bit_definitions.h"

void LedSet(unsigned int);
unsigned int result[20];
unsigned int average;

void main(void)
{

  PCR = CLKDIV_1;                         // ICLK = SYSCLK
  PCR |= PENABLE;                         // enable peripherals

  HETDIR  = 0xFFFFFFFF;                   // set LEDs as outputs
  HETDOUT = 0xFFFFFFFF;                   // turn all LEDs off

  ADCR1 |= PS_8;                          // ADCLK prescaler = 8
  ADSAMPEV |= SEN;                        // ADCSAMP1 controls SW
  ADSAMP1 = 62;                           // SW = 62+2

  ADCR1 |= ADC_EN;                        // Enable ADC
  ADISR1 = 0x0001;                        // group 1 = channel 0
  ADCR2 |= G1_MODE;                       // Continuous Conversion

  ADBCR1 |= BUF_EN;                       // enable buffered mode
  ADBCR1 |= BNDA_8;                       // set RAM boundary between event and group 1
                                          // units of two words from the beginning of buffer
                                          // event group has 8*2 = 16 words for the FIFO
  ADBCR1 |= BNDB_16 + BNDB_2;             // set RAM boundary between group 1 and 2
                                          // units of two words from the beginning of buffer
                                          // group 1 has (18-8)*2 = 20 words for the FIFO
  ADBCR2 |= BNDEND_64;                    // set RAM buffer end boundary
                                          // 64-word FIFO buffer
                                          // group 2 has 64-(2*18) = 28 words for the FIFO


  ADTHRG1 = G1THR_16 + G1THR_4;           // group 1 threshold counter = 20, 20 results will be
                                          // placed on the buffer before setting G1 BUF INT FLAG

  // Loop forever.
  for (;;)
  {
    while(!(ADBUFST & G1_INT_FLAG));      // wait for conversions to complete

    unsigned int i;
    average = 0;
    for (i=0; i<20; i++)
    {
      result[i] = ADBUF1;                 // read FIFO value
      average = average + result[i];      // sum values
    }
    average = (unsigned int) average / 20;// get average
    LedSet(average);
    ADBUFST &= ~G1_INT_FLAG;              // clear flag
  }
}

// display binary value on 16 LEDs
void LedSet(unsigned int mask)
{
  unsigned int out = 0;
  mask ^= 0xFFFFFFFF;

  out |= ((mask & 0x01)   ? 0x00000001 : 0);      // LED on HET0
  out |= ((mask & 0x02)   ? 0x00000004 : 0);      // LED on HET2
  out |= ((mask & 0x04)   ? 0x00000010 : 0);      // LED on HET4
  out |= ((mask & 0x08)   ? 0x00000040 : 0);      // LED on HET6
  out |= ((mask & 0x10)   ? 0x00000080 : 0);      // LED on HET7
  out |= ((mask & 0x20)   ? 0x00000100 : 0);      // LED on HET8
  out |= ((mask & 0x40)   ? 0x00000400 : 0);      // LED on HET10
  out |= ((mask & 0x80)   ? 0x00000800 : 0);      // LED on HET11
  out |= ((mask & 0x100)  ? 0x00001000 : 0);      // LED on HET12
  out |= ((mask & 0x200)  ? 0x00002000 : 0);      // LED on HET13
  out |= ((mask & 0x400)  ? 0x00040000 : 0);      // LED on HET18
  out |= ((mask & 0x800)  ? 0x00080000 : 0);      // LED on HET19
  out |= ((mask & 0x1000) ? 0x00100000 : 0);      // LED on HET20
  out |= ((mask & 0x2000) ? 0x00200000 : 0);      // LED on HET21
  out |= ((mask & 0x4000) ? 0x01000000 : 0);      // LED on HET24
  out |= ((mask & 0x8000) ? 0x80000000 : 0);      // LED on HET31

  HETDOUT = out;
}