wave_dual.c

这是ARM嵌入式开发中定时器的源码

//*-----------------------------------------------------------------------------
//*      ATMEL Microcontroller Software Support  -  ROUSSET  -
//*-----------------------------------------------------------------------------
//* The software is delivered "AS IS" without warranty or condition of any
//* kind, either express, implied or statutory. This includes without
//* limitation any warranty or condition with respect to merchantability or
//* fitness for any particular purpose, or against the infringements of
//* intellectual property rights of others.
//*-----------------------------------------------------------------------------
//* File Name           : wave_dual.c
//* Object              : AT91 - Timer Counter - Dual waveform generation
//*
//* Imported resources  : none
//* Exported resources  : main
//*
//* 1.0 30/09/98 JLV    : Creation
//* 2.0 24/07/00  PF    : Clean up
//*-----------------------------------------------------------------------------
/*
Configure the channel 0 of the Timer Counter (TC) of the AT91
to aim dual waveform generation :
- clock = MCKI / 1024
- Register A = 0x4000 -> toggle TIOA0 when reached
- Register B = 0x6000 -> toggle TIOB0 when reached
- Register C = 0x8000 -> toggle TIOA0 and TIOB0 when reached
  generate trigger to restart the timer
--------------------------------------------------------------------------------
           ________          ________          ______
  TIOA0 __|        |________|        |________|             red LED / output
           ____________      ____________      ______
  TIOB0 __|            |____|            |____|           green LED / output
--------------------------------------------------------------------------------
*/


#include    "periph/stdc/std_c.h"
#include    "targets/eb40/eb40.h"
#include    "parts/r40807/reg_r40807.h"


//*-----------------------------------------------------------------------------
//* Function Name       : main
//* Object              : AT91 - Timer Counter - Dual waveform generation
//* Input Parameters    : none
//* Output Parameters   : none
//* Functions called    : None
//*-----------------------------------------------------------------------------
int main ( void )
//* Begin
{
    /* Enable and clear PIO pin corresponding to TIOA0, TIOB0 and TIOA1 */
    PIO_PER  = ( 1<<PIOTIOA0 ) | (1<<PIOTIOA1) | (1<<PIOTIOB0) ;
    PIO_OER  = ( 1<<PIOTIOA0 ) | (1<<PIOTIOA1) | (1<<PIOTIOB0) ;
    PIO_CODR = ( 1<<PIOTIOA0 ) | (1<<PIOTIOA1) | (1<<PIOTIOB0) ;

    PIO_PDR = (1<<PIOTIOA0) | (1<<PIOTIOB0) ;			/* Define TIOA0 and TIOB0 as peripheral */

    //* Initialize the mode of the timer 0
    TC0_CMR =
		TC_BSWTRG_SET_OUTPUT	|						/* BSWTRG: software trigger set TIOB */
		TC_BCPC_TOGGLE_OUTPUT	|						/* BCPC		: Register C compare toggle TIOB */
		TC_BCPB_TOGGLE_OUTPUT	|						/* BCPC		: Register B compare toggle TIOB */
		TC_ASWTRG_SET_OUTPUT 	|						/* ASWTRG	: software trigger set TIOA */
		TC_ACPC_TOGGLE_OUTPUT	|						/* ACPC		: Register C compare toggle TIOA */
		TC_ACPA_TOGGLE_OUTPUT	|						/* ACPA		: Register A compare toggle TIOA */
		TC_WAVE					|						/* WAVE		: Waveform mode */
		TC_CPCTRG				|						/* CPCTRG	: Register C compare trigger enable	*/
		TC_EEVT_XC0				|						/* EEVT		: XC0 as external event (TIOB = output) */
		TC_CLKS_MCK2 ;									/* TCCLKS	: MCKI / 1024 */


    	TC0_RA = 0x4000 ;								/* Initialize the RA Register value */
    	TC0_RB = 0x6000 ;								/* Initialize the RB Register value */
    	TC0_RC = 0x8000 ;								/* Initialize the RC Register value */
    	TC0_CCR = TC_CLKEN ;							/* Enable the clock of the timer */
    	TC0_CCR = TC_SWTRG ;							/* Trigg the timer */

//* End
    return(0);
}