cx-zivuos/sources/platform_wch_riscv.c

#ifdef ZIVUOS_PLATFORM_WCH_RISCV

#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>

#include <ch32fun.h>
#include <zivuos.h>

#ifndef FUNCONF_SYSTEM_CORE_CLOCK
#error "MCU core clock (FUNCONF_SYSTEM_CORE_CLOCK) not defined."
#endif

#define ZV_TICKS_PER_US ((uint32_t) FUNCONF_SYSTEM_CORE_CLOCK / 1000000)
#define ZV_TICKS_PER_MS ((uint32_t) FUNCONF_SYSTEM_CORE_CLOCK / 1000)

volatile zv_time_t __zv_current_time_miliseconds;

void zv_platform_init(void) {
    __zv_current_time_miliseconds = 0;
    
    SysTick->CTLR = (
        SYSTICK_CTLR_STE |
        SYSTICK_CTLR_STCLK |
        SYSTICK_CTLR_STIE
    );

    NVIC_EnableIRQ(SysTick_IRQn);

    SysTick->CNT = 0x00;
    SysTick->CMP = ZV_TICKS_PER_MS;
}

void SysTick_Handler(void) __attribute__((interrupt));
void SysTick_Handler(void) {
    SysTick->CMP += ZV_TICKS_PER_MS;
    SysTick->SR = 0x00;

    ++__zv_current_time_miliseconds;
}

zv_time_t __zv_platform_get_time_ms(void) {
    return __zv_current_time_miliseconds;
}

zv_ticks_t __zv_platform_get_time_us(void) {
    return SysTick->CNT / ZV_TICKS_PER_US;
}

#endif