/****************************************************************************
Function:
void Delay10us( uint32_t tenMicroSecondCounter )
Description:
This routine performs a software delay in intervals of 10 microseconds.
Precondition:
None
Parameters:
UINT32 tenMicroSecondCounter - number of ten microsecond delays
to perform at once.
Returns:
None
Remarks:
None
***************************************************************************/
void DELAY_10us( uint32_t tenMicroSecondCounter )
{
volatile int32_t cyclesRequiredForEntireDelay;
if(SYS_CLK_FrequencyInstructionGet() <= 500000) //for all FCY speeds under 500KHz (FOSC <= 1MHz)
{
//10 cycles burned through this path (includes return to caller).
//For FOSC == 1MHZ, it takes 5us.
//For FOSC == 4MHZ, it takes 0.5us
//For FOSC == 8MHZ, it takes 0.25us.
//For FOSC == 10MHZ, it takes 0.2us.
}
else
{
//7 cycles burned to this point.
//We want to pre-calculate number of cycles required to delay 10us * tenMicroSecondCounter using a 1 cycle granule.
cyclesRequiredForEntireDelay = (uint32_t)(SYS_CLK_FrequencyInstructionGet()/100000)*tenMicroSecondCounter;
//We subtract all the cycles used up until we reach the while loop below, where each loop cycle count is subtracted.
//Also we subtract the 5 cycle function return.
cyclesRequiredForEntireDelay -= 44; //(29 + 5) + 10 cycles padding
if(cyclesRequiredForEntireDelay <= 0)
{
// If we have exceeded the cycle count already, bail!
}
else
{
while(cyclesRequiredForEntireDelay>0) //19 cycles used to this point.
{
cyclesRequiredForEntireDelay -= 11; //Subtract cycles burned while doing each delay stage, 12 in this case. Add one cycle as padding.
}
}
}
}
void Delay10us(uint32_t dwCount)
{
volatile uint32_t _dcnt;
_dcnt = dwCount * ((uint32_t) (0.00001 / (1.0 / SYS_CLK_FrequencyInstructionGet()) / 10));
while (_dcnt--) {
#if defined(__XC32)
Nop();
Nop();
Nop();
#endif
}
}
