init timer for ppi.c

此为ＡＤＳＰ＿ＢＦ５３３＿ＥＺ＿ＫＩＴ中ＡＤ９２４作DA用时的驱动程序

#include "system.h"

/********************************************************************************/
/***** InitPPI_Timer()														*****/
/***** Configure PPI for output, and DMA channel zero for Writes 			*****/
/********************************************************************************/
void InitPPI_Timer(void)
{
	
	// configure Timer 1 for PPI 1FS GP output mode
	// Frequency is such that 1 half of the DAC output buffer is transmitted between pulses. 
	// Pulse width is 1 PPI clock cycle
	// No interrupts assigned to timer.


	*pTIMER_DISABLE = TIMDIS1;		// disable timer 1
	*pTIMER1_PERIOD = Number_of_DAC_channels * Number_of_Samples ;
	*pTIMER1_WIDTH   = 0x001;
	*pTIMER1_CONFIG   = PWM_OUT | PULSE_HI | PERIOD_CNT | CLK_SEL | EMU_RUN;	// will need to be written again after PPI is initialised and enabled.
	asm("ssync;");

}