Last active
February 7, 2022 15:43
-
-
Save itrobotics/23a7cedd16f8b7bc11c9 to your computer and use it in GitHub Desktop.
Systimer
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
void My_Main(void) | |
{ | |
GPIO_GPFSEL4 |= (0x1 << 21); | |
GPIO_GPFSEL4 &= ~(0x6 << 21); | |
// set bit 21~23 to 0b001, so GPIO 47 is an output pin | |
GPIO_GPCLR1 |= (0x1 << 15); // set GPIO 47 output low (LED off) | |
INT_DISIRQ1 = 0xFFFFFFFF; | |
INT_DISIRQ2 = 0xFFFFFFFF; | |
INT_DISBIRQ = 0xFF; | |
// disable all interrupts | |
STIMER_CTRL = 0x2; | |
// clear system timer cmp1 pending | |
STIMER_CMP1 = STIMER_COUNT_L + INTREVAL; | |
// set interval | |
INT_ENIRQ1 = 0x2; | |
// enable system timer 1 interrupt | |
__asm__("MRS r0, CPSR\n\t" | |
"BIC r0, r0, #0x80\n\t" | |
"MSR CPSR_c, r0"); //enable IRQ | |
while(1) {} // block here | |
} | |
void ISR_IRQ(void) | |
{ | |
if(INT_IRQ_PEND1 & 0x2) // system timer cmp1 interrupt | |
{ | |
STIMER_CMP1 = STIMER_COUNT_L + INTREVAL; | |
// set interval | |
if(led_status == 0) | |
{ | |
GPIO_GPSET1 |= (0x1 << 15); // set GPIO 47 output high (LED on) | |
led_status = 1; | |
} | |
else | |
{ | |
GPIO_GPCLR1 |= (0x1 << 15); // set GPIO 47 output low (LED off) | |
led_status = 0; | |
} | |
STIMER_CTRL = 0x2; | |
// clear system timer cmp1 pending | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment