TMS320F280049C: EQEP Calculation Doubt

Hi,

I am working on the EQEP project, more specifically eqep_ex2_pos_speed.c to obtain motor speed and angle.

Could you please explain the reason why they are doing this?  p->thetaMech &= 0x7FFF

I have given the code snippet below -

 // The following lines calculate
    //
    // p->thetaMech ~= QPOSCNT / mechScaler [current cnt/(total cnt in 1 rev)]
    //
    // where mechScaler = 4000 cnts/revolution
    //
    temp = (int32_t)p->thetaRaw * (int32_t)p->mechScaler;   // Q0 * Q26 = Q26
    temp &= 0x03FFF000;

    p->thetaMech = (int16_t)(temp >> 11);                    // Q26 -> Q15
    p->thetaMech &= 0x7FFF;