tms470r1b1m_adc10_01.c

TMS470的ＡＤＣ总线源码

//******************************************************************************
//  TMS470 Demo - MibADC Sample ADIN0, Set HET0 if > 0.5*AVcc
//
//  Description; A single sample is made on ADIN0 with reference to AVcc/AVss.
//  Software sets starts sample and conversion and polls for end of conversion.
//  If A0 > 0.5*AVcc, HET0 set, else reset.
//
//  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|---> LED
//            |                 |
//
//
//  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 |= ACQ_128 + PS_8;                // ACQ 128, prescaler = 8
  ADCR1 |= ADC_EN;                        // Enable ADC

  for (;;)
  {
    ADISR1 = 0x0001;                      // Convert croup 1 = channel 0
    while (!(ADSR & GP1_END));            // Wait for conversion to complete
    if (ADDR0 < 0x1FF)                    // Reading clears flag
      HETDOUT &= ~0x01;
    else
      HETDOUT |= 0x01;
  }
}