I have a strange problem with kea8.It
- My core clock is FEI mode ,48Mhz,and bus clock is 24Mhz.And configure code as below:
ICS_C2 = 0x20;
ICS_C1 = 0x04;
while ((ICS_S & ICS_S_LOCK_MASK) == 0);
SIM_CLKDIV = 0x01100000;
ICS_C2 = 0x00;
- I use systick to make a 1ms interrupt.And configure code as below:
/*!Comment:Set the systick timer as 1ms.*/
SYST_RVR = 48000u;
/*!Comment:set systick source clock.*/
SYST_CSR |= (1 << 2);
SYST_CSR |= (1 << 0);
SYST_CSR |= (1 << 1);
/*!Comment:Catch the first time entering interrupt.*/
GPIOA_PTOR |= (1 << 13u);
- The GPIO is correctly configured.When I power on the device ,It delay about 120ms to enter the first interrupt handle function "SysTick_Handler".If I use PIT module instead of systick,the delay time will decreace to 20~30ms.
I want to fix the delay time of systick timer?I use other chip like kea64 FEE mode with systick timer will not have this problem,it delay 20~30ms,too.
I want to know the minimal time to initialize clock FEI and FEE mode(KEA8 KEA64) .