//###########################################################################
//
// FILE:	Example_freqcal.h
//
// TITLE:	Frequency measurement using EQEP peripheral
//
// DESCRIPTION: Header file containing data type and object definitions and
// initializers.
//
//###########################################################################
// $TI Release: $
// $Release Date: $
// $Copyright:
// Copyright (C) 2009-2023 Texas Instruments Incorporated - http://www.ti.com/
//
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// 
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// 
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// 
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//###########################################################################

#ifndef __FREQCAL__
#define __FREQCAL__

//
// Included Files
//
#include "IQmathLib.h"         // Include header for IQmath library

//
// Typedef structure of the FREQCAL Object
//
typedef struct 
{
    //
    // Scaler converting 1/N cycles to a GLOBAL_Q freq (Q0)
    // independently with global Q
    //
    Uint32 freqScaler_pr;
    
    //
    // Scaler converting 1/N cycles to a GLOBAL_Q freq (Q0)
    // independently with global Q
    //
    Uint32 freqScaler_fr;
    Uint32 BaseFreq;        // Parameter : Maximum Freq
    _iq freq_pr;            // Output :  Freq in per-unit using capture unit
    int32 freqhz_pr;        // Output: Freq in Hz, measured using Capture unit
    Uint32 oldpos;
    _iq freq_fr;            // Output : Freq in per-unit using position counter
    int32 freqhz_fr; 	    // Output: Freq in Hz, measured using Capture unit
    void (*init)();     	// Pointer to the init function
    void (*calc)();    		// Pointer to the calc function
} FREQCAL;

//
// Define for a QEP_handle
//
typedef FREQCAL *FREQCAL_handle;

//
// Default initializer for the FREQCAL Object
//
#if (CPU_FRQ_150MHZ)
    #define FREQCAL_DEFAULTS {\
        234,200,10000,0,0,\
        0,0,0,\
        (void (*)(long))FREQCAL_Init,\
        (void (*)(long))FREQCAL_Calc }
#endif
#if (CPU_FRQ_100MHZ)
    #define FREQCAL_DEFAULTS {\
        313,200,10000,0,0,\
        0,0,0,\
        (void (*)(long))FREQCAL_Init,\
        (void (*)(long))FREQCAL_Calc }
#endif

//
// Function Prototypes
//
void FREQCAL_Init(void);
void FREQCAL_Calc(FREQCAL_handle);

#endif /*  __FREQCAL__ */

//
//	For 150 MHz Operation:
//
//	1. freqScaler_fr
//	   v = (x2-x1)/T     - Equation 1
//
//	 If max/base freq = 10kHz:   10kHz = (x2-x1)/(2/100Hz)        - Equation 2
//	                      max (x2-x1) = 200 counts = freqScaler_fr
//			Note: T = 2/100Hz. 2 is from (x2-x1)/2 - because QPOSCNT counts 
//			      2 edges per cycle (rising and falling)
//	   freqhz_fr = 200 default
//
//	2. min freq = 1 count/(2/100Hz) = 50 Hz
//
//	3. freqScaler_pr
//	   v = X/(t2-t1)     - Equation 4
//
//	 If max/base freq = 10kHz:  10kHz = 8/(2T)
//	        where 4 = QCAPCTL [UPPS] (Unit timeout - once every 4 edges)
//			 T = time in seconds = t2-t1/(150MHz/128),  
//                                 t2-t1= # of QCAPCLK cycles, and
//			                       1 QCAPCLK cycle = 1/(150MHz/128) = QCPRDLAT
//													 
//	So: 10 kHz = 4(150MHz/128)/2(t2-t1)
//       Equation 5
//	     t2-t1 = 4(150MHz/128)/(10kHz*2) = (150MHz/128)/(2*10kHz/4)
//	           = 234 seconds = maximum (t2-t1) = freqScaler_pr
//	   freqhz_pr = 234 default
//
//
//	For 100 MHz Operation:
//
//	The same calculations as above are performed, but with 100 MHz
//	instead of 150MHz when calculation freqhr_pr, and at UPPS of 8 instead
//	of 4. The value for freqScaler_pr becomes: (100MHz/128)/(2*10kHz/8) = 313
//	More detailed calculation results can be found in the Example_freqcal.xls
//	spreadsheet included in the example folder.
//

//
// End of File
//