www.pudn.com > steper8.zip > DSP28_CpuTimers.c, change:2003-07-16,size:3808b


// 
//      TMDX ALPHA RELEASE 
//      Intended for product evaluation purposes 
// 
//########################################################################### 
// 
// FILE:	DSP28_CpuTimers.c 
// 
// TITLE:	DSP28 CPU 32-bit Timers Initialization & Support Functions. 
// 
//########################################################################### 
// 
//  Ver | dd mmm yyyy | Who  | Description of changes 
// =====|=============|======|=============================================== 
//  0.55| 06 May 2002 | L.H. | EzDSP Alpha Release 
//  0.56| 20 May 2002 | L.H. | No change 
//  0.57| 27 May 2002 | L.H. | No change 
//########################################################################### 
 
#include "DSP28_Device.h" 
 
struct CPUTIMER_VARS CpuTimer0; 
struct CPUTIMER_VARS CpuTimer1; 
struct CPUTIMER_VARS CpuTimer2; 
 
//--------------------------------------------------------------------------- 
// InitCpuTimers:  
//--------------------------------------------------------------------------- 
// This function initializes all three CPU timers to a known state. 
// 
void InitCpuTimers(void) 
{ 
	// Initialize address pointers to respective timer registers: 
	CpuTimer0.RegsAddr = &CpuTimer0Regs; 
	CpuTimer1.RegsAddr = &CpuTimer1Regs; 
	CpuTimer2.RegsAddr = &CpuTimer2Regs; 
 
	// Initialize timer period to maximum:	 
	CpuTimer0Regs.PRD.all  = 0xFFFFFFFF; 
	CpuTimer1Regs.PRD.all  = 0xFFFFFFFF; 
	CpuTimer2Regs.PRD.all  = 0xFFFFFFFF; 
 
	// Initialize pre-scale counter to divide by 1 (SYSCLKOUT):	 
	CpuTimer0Regs.TPR.all  = 0; 
	CpuTimer0Regs.TPRH.all = 0; 
	 
	// Make sure timers are stopped: 
	CpuTimer0Regs.TCR.bit.TSS = 1;              
	CpuTimer1Regs.TCR.bit.TSS = 1;              
	CpuTimer2Regs.TCR.bit.TSS = 1;              
 
	// Reload all counter registers with period values: 
	CpuTimer0Regs.TCR.bit.TRB = 1;              
	CpuTimer1Regs.TCR.bit.TRB = 1;              
	CpuTimer2Regs.TCR.bit.TRB = 1;              
	 
	// Reset interrupt counters: 
	CpuTimer0.InterruptCount = 0; 
	CpuTimer1.InterruptCount = 0; 
	CpuTimer2.InterruptCount = 0; 
}	 
	 
//--------------------------------------------------------------------------- 
// 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.POL = 0;      // 0 = Pulse Low 
	Timer->RegsAddr->TCR.bit.TOG =	0;     // 0 = No Toggle, POL bit defines action 
	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.FRCEN = 0;    // Force output enable (not used) 
	Timer->RegsAddr->TCR.bit.PWIDTH = 7;   // 7+1 = 8 SYSCLKOUT cycle pulse width  
	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. 
//===========================================================================