dsp2812cputimers.c

来自「TMS320F2812的bootloader源程序」· C语言 代码 · 共 76 行

//###########################################################################
//
// FileName:	DSP2812CpuTimers.c
///
// WrittenBy:	PangCheng Syokean LTD. Nanning GX 
//
// Date:		2005-7-14
//           
//###########################################################################
#ifndef DSP281X_DEVICE_H
#include "DSP281x_Device.h"     // DSP281x Headerfile Include File
#endif
////////////////////////////////////////////////////////////////////
struct CPUTIMER_VARS CpuTimer0;
void ConfigCpuTimer(struct CPUTIMER_VARS *Timer, float Freq, float Period);
void InitCpuTimers(void);

//---------------------------------------------------------------------------
// InitCpuTimers: 
//---------------------------------------------------------------------------
// This function initializes all three CPU timers to a known state.
void InitCpuTimers(void)
{
    // CPU Timer 0
	// Initialize address pointers to respective timer registers:
	CpuTimer0.RegsAddr = &CpuTimer0Regs;
	// Initialize timer period to maximum:	
	CpuTimer0Regs.PRD.all  = 0xFFFFFFFF;
	// Initialize pre-scale counter to divide by 1 (SYSCLKOUT):	
	CpuTimer0Regs.TPR.all  = 0;
	CpuTimer0Regs.TPRH.all = 0;
	// Make sure timer is stopped:
	CpuTimer0Regs.TCR.bit.TSS = 1;
	// Reload all counter register with period value:
	CpuTimer0Regs.TCR.bit.TRB = 1;
	// Reset interrupt counters:
	CpuTimer0.InterruptCount = 0;	             	
}	
	
//---------------------------------------------------------------------------
// Function: ConfigCpuTimer: 
//---------------------------------------------------------------------------
// This function initializes the selected timer to the period specified
// by the "Freq" and "Period" parameters. The "Freq" is entered as "MHz"
// and the period in "uSeconds". The timer is held in the stopped state
// after configuration.
//
void ConfigCpuTimer(struct CPUTIMER_VARS *Timer, float Freq, float Period)
{
	Uint32 	temp;
	
	// Initialize timer period:	
	Timer->CPUFreqInMHz = Freq;
	Timer->PeriodInUSec = Period;
	temp = (long) (Freq * Period);
	Timer->RegsAddr->PRD.all = temp;

	// Set pre-scale counter to divide by 1 (SYSCLKOUT):	
	Timer->RegsAddr->TPR.all  = 0;
	Timer->RegsAddr->TPRH.all  = 0;
	
	// Initialize timer control register:
	Timer->RegsAddr->TCR.bit.TSS = 1;      // 1 = Stop timer, 0 = Start/Restart Timer 
	Timer->RegsAddr->TCR.bit.TRB = 1;      // 1 = reload timer
	Timer->RegsAddr->TCR.bit.SOFT = 1;
	Timer->RegsAddr->TCR.bit.FREE = 1;     // Timer Free Run
	Timer->RegsAddr->TCR.bit.TIE = 1;      // 0 = Disable/ 1 = Enable Timer Interrupt
	
	// Reset interrupt counter:
	Timer->InterruptCount = 0;
}

//===========================================================================
// No more.
//===========================================================================