/* ================================================================================
==

File name:       F281XQEP.C

                    

Originator:    Digital Control Systems Group

            Texas Instruments



Description:   This file contains source for the QEP drivers for the F281X



Target: TMS320F281x family

          

================================================================================
=====

History:

-------------------------------------------------------------------------------------

04-15-2005    Version 3.20: Using DSP281x v. 1.00 or higher

----------------------------------------------------------------------------------*/



#include "DSP281x_Device.h"

#include "f281xqep.h"



void  F281X_EV1_QEP_Init(QEP *p)

{



          EvaRegs.CAPCONA.all = QEP_CAP_INIT_STATE;    // Set up capture units

          EvaRegs.T2CON.all = QEP_TIMER_INIT_STATE;    // Set up capture timer

          EvaRegs.T2PR = 4*p->LineEncoder;             // Init Timer 1 period Register

          EvaRegs.EVAIFRC.bit.CAP3INT = 1;     // Clear CAP3 flag

          EvaRegs.EVAIMRC.bit.CAP3INT = 1;     // Enable CAP3 Interrupt



          EALLOW;                       // Enable EALLOW

          GpioMuxRegs.GPAMUX.all |= 0x0700;     // Set up the capture pins to primary functions

          EDIS;                         // Disable EALLOW

}





void F281X_EV1_QEP_Calc(QEP *p)

{



     int32 Tmp;



// Check the rotational direction

     p->DirectionQep = 0x4000&EvaRegs.GPTCONA.all;

     p->DirectionQep = p->DirectionQep>>14;



// Check the timer 2 counter for QEP

     p->RawTheta = EvaRegs.T2CNT + p->CalibratedAngle;



// Compute the mechanical angle in Q15

     Tmp = __qmpy32by16(p->MechScaler,p->RawTheta,31);    // Q15 = Q30*Q0

     p->MechTheta = (int16)(Tmp);                         // Q15 -> Q15

     p->MechTheta &= 0x7FFF;                              // Wrap around 0x07FFF



// Compute the electrical angle in Q15

     p->ElecTheta = p->PolePairs*p->MechTheta;            // Q0*Q15 = Q15

     p->ElecTheta &= 0x7FFF;                              // Wrap around 0x07FFF

}



void F281X_EV1_QEP_Isr(QEP *p)

{



     p->QepCountIndex = EvaRegs.T2CNT;    // Get the timer 2 counter for one mechanical revolution

     EvaRegs.T2CNT = 0;                   // Reset the timer 2 counter

     p->IndexSyncFlag = 0x00F0;           // Set the index flag



}