tms470r1b1m_adc10_02.c

TMS470的ＡＤＣ总线源码

//******************************************************************************
//  TMS470 Demo - MibADC Sample ADIN0 Continuous 32KSPS
//
//  Description; A single sample is made continuously  ADIN0 with reference to
//  AVcc/AVss. Software toggles HET after each conversion
//  Software sets starts sample and conversion and polls for end of conversion.
//
//  Total sample and convert time = 19.6608 MHz/(8*((62+2)+11)) = 32.7KSPS
//  SYSCLK = MCLK = ACLK = 8 x 7.3728MHz = 58.9824MHz
//  ICLK = SYSCLK / 3 = 19.6608MHz
//
//  //*An external 7.3728MHz XTAL with proper load caps is required*//
//
//              TMS-FET470B1M
//             -----------------
//            |            OSCIN|-
//         +--|PLLDIS           | 7.3728MHz
//         |  |           OSCOUT|-
//        -+- |                 |
//            |                 |
//        >---|ADIN0        HET0|---> Toggle
//            |                 |
//
//  L.Westlund / J.Mangino
//  Texas Instruments, Inc
//  July 29th 2005
//  Built with IAR Embedded Workbench Version: 4.30A
//******************************************************************************

#include <intrinsic.h>
#include "iotms470r1b1m.h"
#include "tms470r1b1m_bit_definitions.h"

void main(void)
{
  PCR = CLKDIV_3;                         // ICLK = SYSCLK / 3
  GCR = ZPLL_CLK_DIV_PRE_1;               // SYSCLK = 8 x fOSC
  PCR |= PENABLE;                         // Enable peripherals

  HETDIR  = 0xFFFFFFFF;                   // HETx Output direction
  HETDOUT = 0x00000000;

  ADCR1 |= PS_8;                          // ADCLK prescaler = 8
  ADSAMPEV |= SEN;                        // ADCSAMP1 controls SW
  ADSAMP1 = 62;                           // SW = 62+2
  ADCR1 |= ADC_EN;                        // Enable ADC
  ADISR1 = 0x0001;                        // Convert croup 1 = channel 0
  ADCR2 |= G1_MODE;                       // Continuous Conversion

  for (;;)
  {
    while (!(ADSR & GP1_END));            // Wait for conversion to complete
    HETDOUT ^= 0x00000001;                // Toggle
    ADSR |= GP1_END;                      // Clears flag
  }
}