4.1. MTIMER - System Timer

This demo is based on a 64-bit timer (MTIMER) that comes with the risc-v kernel. This demo can provide reference for os tick.

4.1.1. Hardware Connection

None

4.1.2. Software Implementation

• See examples/systick for the software code

备注

The mtimer clock defaults to 1M after frequency division, which is convenient for later use and reduces calculation time.

void systick_isr()
{
    static uint32_t tick=0;
    tick++;
    MSG("tick:%d\r\n",tick);
}

bflb_platform_set_alarm_time(1000000,systick_isr);

• Use the above code to set the mtimer timing time to 1s, and register the interrupt callback function.

4.1.3. Compile and Program

• CDK compilation

  Open project:systick.cdkproj

  Refer to the steps of Guide to using CDK (like MDK Keil) under Windows to compile and download

• Command compilation

$ cd <sdk_path>/bl_mcu_sdk
$ make BOARD=bl706_iot APP=systick

• Program

  See BLDevCube start guide

4.1.4. Experimental Phenomena

The tick value is incremented by 1 per second and printed through the serial port.