DSP2803x_CpuTimers.c

//###########################################################################
//
// FILE:	DSP2803x_CpuTimers.c
//
// TITLE:	CPU 32-bit Timers Initialization & Support Functions.
//
//###########################################################################
// $TI Release: F2803x Support Library v2.02.00.00 $
// $Release Date: Sun Oct  4 16:06:22 IST 2020 $
// $Copyright:
// Copyright (C) 2009-2020 Texas Instruments Incorporated - http://www.ti.com/
//
// Redistribution and use in source and binary forms, with or without 
// modification, are permitted provided that the following conditions 
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// 
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// 
//   Redistributions in binary form must reproduce the above copyright
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//   distribution.
// 
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//   its contributors may be used to endorse or promote products derived
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// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
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// $
//###########################################################################

//
// Included Files
//
#include "DSP2803x_Device.h"     // Headerfile Include File
#include "DSP2803x_Examples.h"   // Examples Include File

//
// Globals
//
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)
{
    //
    // 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;

    //
    // CPU Timer 1 and 2
    // Initialize address pointers to respective timer registers
    //
    CpuTimer1.RegsAddr = &CpuTimer1Regs;
    CpuTimer2.RegsAddr = &CpuTimer2Regs;

    //
    // Initialize timer period to maximum
    //
    CpuTimer1Regs.PRD.all  = 0xFFFFFFFF;
    CpuTimer2Regs.PRD.all  = 0xFFFFFFFF;

    //
    // Initialize pre-scale counter to divide by 1 (SYSCLKOUT)
    //
    CpuTimer1Regs.TPR.all  = 0;
    CpuTimer1Regs.TPRH.all = 0;
    CpuTimer2Regs.TPR.all  = 0;
    CpuTimer2Regs.TPRH.all = 0;

    //
    // Make sure timers are stopped
    //
    CpuTimer1Regs.TCR.bit.TSS = 1;
    CpuTimer2Regs.TCR.bit.TSS = 1;

    //
    // Reload all counter register with period value
    //
    CpuTimer1Regs.TCR.bit.TRB = 1;
    CpuTimer2Regs.TCR.bit.TRB = 1;

    //
    // Reset interrupt counters
    //
    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     PeriodInClocks;
    
    //
    // Initialize timer period
    //
    Timer->CPUFreqInMHz = Freq;
    Timer->PeriodInUSec = Period;
    PeriodInClocks = (long) (Freq * Period);
    
    //
    // Counter decrements PRD+1 times each period
    //
    Timer->RegsAddr->PRD.all = PeriodInClocks - 1;
    
    //
    // Set pre-scale counter to divide by 1 (SYSCLKOUT)
    //
    Timer->RegsAddr->TPR.all  = 0;
    Timer->RegsAddr->TPRH.all  = 0;
    
    //
    // Initialize timer control register
    //

    //
    // 1 = Stop timer, 0 = Start/Restart Timer    
    //
    Timer->RegsAddr->TCR.bit.TSS = 1;
    
    Timer->RegsAddr->TCR.bit.TRB = 1;       // 1 = reload timer
    Timer->RegsAddr->TCR.bit.SOFT = 0;
    Timer->RegsAddr->TCR.bit.FREE = 0;      // Timer Free Run Disabled
    
    //
    // 0 = Disable/ 1 = Enable Timer Interrupt
    //
    Timer->RegsAddr->TCR.bit.TIE = 1;   
    
    //
    // Reset interrupt counter
    //
    Timer->InterruptCount = 0;
}

//
// End of File
//