62 lines
1.1 KiB
C
62 lines
1.1 KiB
C
|
#include <stdio.h>
|
||
|
|
|
||
|
|
#define TIMER (*(uint64_t *)0x40004000)
|
||
|
|
#define TIMER_CMP (*(uint64_t *)0x40004008)
|
||
|
|
#define TRACE (*(unsigned char *)0x40000000)
|
||
|
|
|
||
|
|
volatile int ticks = 0;
|
||
|
|
|
||
|
|
int _write(int file, const char *ptr, int len) {
|
||
|
|
int x;
|
||
|
|
|
||
|
|
for (x = 0; x < len; x++) {
|
||
|
|
TRACE = *ptr++;
|
||
|
|
}
|
||
|
|
|
||
|
|
return (len);
|
||
|
|
}
|
||
|
|
|
||
|
|
void timer_ISR() {
|
||
|
|
uint32_t timer_value;
|
||
|
|
|
||
|
|
ticks++;
|
||
|
|
// timer_value = TIMER;
|
||
|
|
// TIMER_CMP = timer_value + 1000;
|
||
|
|
}
|
||
|
|
|
||
|
|
void register_timer_isr() {
|
||
|
|
asm volatile("la t0, TIMER_CMP_INT \n csrw mtvec, t0");
|
||
|
|
asm volatile("li t1, 0x888 \n csrw mie, t1");
|
||
|
|
}
|
||
|
|
|
||
|
|
int main(void) {
|
||
|
|
|
||
|
|
uint32_t timer_value;
|
||
|
|
uint32_t start_time;
|
||
|
|
|
||
|
|
register_timer_isr();
|
||
|
|
|
||
|
|
start_time = TIMER;
|
||
|
|
TIMER_CMP = start_time + 10000;
|
||
|
|
printf("set timer to %ld ns\n", start_time + 10000);
|
||
|
|
|
||
|
|
do {
|
||
|
|
timer_value = TIMER;
|
||
|
|
} while (timer_value < start_time + 200000);
|
||
|
|
|
||
|
|
start_time = TIMER;
|
||
|
|
TIMER_CMP = start_time + 10000;
|
||
|
|
printf("set timer to %ld ns\n", start_time + 10000);
|
||
|
|
|
||
|
|
do {
|
||
|
|
timer_value = TIMER;
|
||
|
|
} while (timer_value < start_time + 200000);
|
||
|
|
|
||
|
|
|
||
|
|
printf("Timer: %ld ns\n", timer_value);
|
||
|
|
printf("ticks: %ld\n", ticks);
|
||
|
|
asm volatile ("ecall");
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
}
|