Posted on May 17, 2011 at 09:55Hi all,
By s/w delay I mean to say simple for loop.
Clock configuration done is as follows:
/*wait state insertion: This function should be executed from
SRAM when*/
/*booting from bank1 to avoid Read-While-Write from the same Bank.*/
FMI_Config (FMI_READ_WAIT_STATE_2, FMI_WRITE_WAIT_STATE_0,FMI_PWD_ENABLE,
FMI_LVD_ENABLE, FMI_FREQ_HIGH);/*Insert 2 Wait States for
read*/
SCU_PLLFactorsConfig (192, 25, 2); /* PLL factors Configuration based
on*/ /* a OSC/Crystal value = 25 MHz*/
SCU_PLLCmd (ENABLE); /* PLL Enable and wait for Locking*/
SCU_RCLKDivisorConfig (SCU_RCLK_Div1); /* RCLK @96Mhz */
SCU_HCLKDivisorConfig (SCU_HCLK_Div1); /* AHB @96Mhz */
SCU_FMICLKDivisorConfig (SCU_FMICLK_Div1);/* FMI @96Mhz */
SCU_PCLKDivisorConfig (SCU_PCLK_Div2); /* APB @48Mhz */
SCU_MCLKSourceConfig (SCU_MCLK_PLL); /* MCLK @96Mhz */
Delay Function:
// ms delay
void Delay(unsigned int uint_TimeDelay)
{
unsigned int l_uintdelay1, l_uintdelay2;
for (l_uintdelay2 = 0; l_uintdelay2 < uint_TimeDelay; l_uintdelay2++)
{
//approx: 96000 instruction execution time (at 96 MHz MCLK) = 1ms
minimum
for (l_uintdelay1 = 0;l_uintdelay1
for (l_uintdelay1 = 0;l_uintdelay1
}
}
Delay used in application:
while(1)
{
GPIO_WriteBit(GPIO9,GPIO_Pin_3,Bit_RESET);
Delay(1);
GPIO_WriteBit(GPIO9,GPIO_Pin_3,Bit_SET);
Delay(1);
}
Expected Waveform (GPIO9.3):
OFF time: 1 ms min
ON time: 1 ms min
Waveform observed on Oscilloscope (GPIO9.3):
OFF time: 1 us
ON time: 1.36 us
I am using RIDE7 debugger.Crystal used is of 25MHz.So delay should be more than the expected but how it can be less than the expected?
Regards
Sai
