179 lines
6.9 KiB
C
179 lines
6.9 KiB
C
// TI File $Revision: /main/12 $
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// Checkin $Date: July 10, 2008 11:07:26 $
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//###########################################################################
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//
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// FILE: Example_2833xEqep_freqcal.c
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//
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// TITLE: Frequency measurement using EQEP peripheral
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//
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// ASSUMPTIONS:
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//
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// This program requires the DSP2833x header files.
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// As supplied, this project is configured for "boot to SARAM" operation.
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//
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// Test requires the following hardware connections
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//
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// GPIO20/EQEP1A <- External input - connect to GPIO0/EPWM1A
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//
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// As supplied, this project is configured for "boot to SARAM"
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// operation. The 2833x Boot Mode table is shown below.
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// For information on configuring the boot mode of an eZdsp,
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// please refer to the documentation included with the eZdsp,
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//
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// $Boot_Table:
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//
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// GPIO87 GPIO86 GPIO85 GPIO84
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// XA15 XA14 XA13 XA12
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// PU PU PU PU
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// ==========================================
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// 1 1 1 1 Jump to Flash
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// 1 1 1 0 SCI-A boot
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// 1 1 0 1 SPI-A boot
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// 1 1 0 0 I2C-A boot
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// 1 0 1 1 eCAN-A boot
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// 1 0 1 0 McBSP-A boot
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// 1 0 0 1 Jump to XINTF x16
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// 1 0 0 0 Jump to XINTF x32
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// 0 1 1 1 Jump to OTP
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// 0 1 1 0 Parallel GPIO I/O boot
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// 0 1 0 1 Parallel XINTF boot
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// 0 1 0 0 Jump to SARAM <- "boot to SARAM"
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// 0 0 1 1 Branch to check boot mode
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// 0 0 1 0 Boot to flash, bypass ADC cal
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// 0 0 0 1 Boot to SARAM, bypass ADC cal
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// 0 0 0 0 Boot to SCI-A, bypass ADC cal
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// Boot_Table_End$
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//
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// DESCRIPTION:
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//
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// This test will provide frequency measurement using capture unit (freqhz_pr)
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// and unit time out (freqhz_fr). The EPWM1A frequency will be measured by the EQEP.
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//
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// By default, EPWM1A is configured to generate a frequency of 5 kHz - measured
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// frequency found in freqhz_pr and freqhz_fr should be 5000.
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//
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// See DESCRIPTION in Example_freqcal.c for more details on the frequency calculation
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// performed in this example.
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//
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// In addition to this file, the following files must be included in this project:
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// Example_freqcal.c - includes all eQEP functions
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// Example_EPwmSetup.c - sets up EPWM1A for use with this example
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// Example_freqcalh - includes initialization values for frequency structure.
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//
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// * Maximum frequency is configured to 10Khz (BaseFreq)
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// * Minimum frequency is assumed at 50Hz for capture pre-scalar selection
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//
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// SPEED_FR: High Frequency Measurement is obtained by counting the external input pulses
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// for 10ms (unit timer set to 100Hz).
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//
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// SPEED_FR = { (Count Delta)/10ms }
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//
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//
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// SPEED_PR: Low Frequency Measurement is obtained by measuring time period of input edges.
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// Time measurement is averaged over 64edges for better results and
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// capture unit performs the time measurement using pre-scaled SYSCLK
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//
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// Note that pre-scaler for capture unit clock is selected such that
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// capture timer does not overflow at the required minimum frequency
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//
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// This example runs forever until the user stops it.
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//
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//
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// Watch Variables: freq.freqhz_fr - Frequency measurement using position counter/unit time out
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// freq.freqhz_pr - Frequency measurement using capture unit
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//
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//###########################################################################
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// Original Author: SD
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//
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// $TI Release: DSP2833x/DSP2823x Header Files V1.20 $
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// $Release Date: August 1, 2008 $
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//###########################################################################
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#include "DSP28x_Project.h" // Device Headerfile and Examples Include File
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#include "Example_freqcal.h" // Example specific include file
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void EPwmSetup(void);
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interrupt void prdTick(void);
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FREQCAL freq=FREQCAL_DEFAULTS;
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void main(void)
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{
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// Step 1. Initialize System Control:
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// PLL, WatchDog, enable Peripheral Clocks
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// This example function is found in the DSP2833x_SysCtrl.c file.
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InitSysCtrl();
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// Step 2. Initalize GPIO:
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// This example function is found in the DSP2833x_Gpio.c file and
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// illustrates how to set the GPIO to it's default state.
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// InitGpio(); // Skipped for this example
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// Only init the GPIO for EQep1 and EPwm1 in this case
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// This function is found in DSP2833x_EQep.c
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InitEQep1Gpio();
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InitEPwm1Gpio();
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// Step 3. Clear all interrupts and initialize PIE vector table:
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// Disable CPU interrupts
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DINT;
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// Initialize the PIE control registers to their default state.
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// The default state is all PIE interrupts disabled and flags
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// are cleared.
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// This function is found in the DSP2833x_PieCtrl.c file.
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InitPieCtrl();
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// Disable CPU interrupts and clear all CPU interrupt flags:
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IER = 0x0000;
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IFR = 0x0000;
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// Initialize the PIE vector table with pointers to the shell Interrupt
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// Service Routines (ISR).
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// This will populate the entire table, even if the interrupt
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// is not used in this example. This is useful for debug purposes.
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// The shell ISR routines are found in DSP2833x_DefaultIsr.c.
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// This function is found in DSP2833x_PieVect.c.
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InitPieVectTable();
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// Interrupts that are used in this example are re-mapped to
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// ISR functions found within this file.
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EALLOW; // This is needed to write to EALLOW protected registers
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PieVectTable.EPWM1_INT= &prdTick;
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EDIS; // This is needed to disable write to EALLOW protected registers
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// Step 4. Initialize all the Device Peripherals:
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// Example specific ePWM setup. This function is found
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// in Example_EPwmSetup.c
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EPwmSetup();
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// Step 5. User specific code, enable interrupts:
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// Enable CPU INT1 which is connected to CPU-Timer 0:
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IER |= M_INT3;
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// Enable TINT0 in the PIE: Group 3 interrupt 1
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PieCtrlRegs.PIEIER3.bit.INTx1 = 1;
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// Enable global Interrupts and higher priority real-time debug events:
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EINT; // Enable Global interrupt INTM
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ERTM; // Enable Global realtime interrupt DBGM
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freq.init(&freq); // Initializes eQEP for frequency calculation in
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// FREQCAL_Init(void)function in Example_EPwmSetup.c
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for(;;)
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{
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}
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}
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interrupt void prdTick(void) // Interrupts once per ePWM period
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{
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freq.calc(&freq); // Checks for event and calculates frequency in FREQCAL_Calc(FREQCAL *p)
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// function in Example_EPwmSetup.c
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// Acknowledge this interrupt to receive more interrupts from group 1
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PieCtrlRegs.PIEACK.all = PIEACK_GROUP3;
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EPwm1Regs.ETCLR.bit.INT=1;
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}
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