clock_trim_scan.c File Reference

#include "fw_hal.h"

Go to the source code of this file.

Functions
uint8_t	readCode (uint8_t offset)
void	main (void)

Function Documentation

main()

void main

(

void

)

Definition at line 36 of file clock_trim_scan.c.

{
    uint8_t i, j, vrtrim = 0x01, irtrim = 0;
 
    // Set system clock. Invoke it to set the frequency band
    SYS_SetClock();
    // UART1 configuration: baud 115200 with Timer2, 1T mode, no interrupt
    UART1_Config8bitUart(UART1_BaudSource_Timer2, HAL_State_ON, 115200);
 
    while(1)
    {
        // The upper limit of IRTRIM depends on VRTRIM, MCU becomes unstable if it goes 
        // too high, set 0x30 to a lower value if scan stucks at beginning
        if (++irtrim == 0x30 + vrtrim) 
        {
            irtrim = 0x00;
            // VRTRIM controls the voltage level, normally it won't exceed 0x40
            if (++vrtrim == 0x40) 
            {
                vrtrim = 0x00;
            }
        }
        SYS_TrimClock(vrtrim, irtrim);
 
        UART1_TxString("ADDR: 0x");
        UART1_TxHex(__CID_ADDR >> 8);
        UART1_TxHex(__CID_ADDR & 0xFF);
        UART1_TxString("\r\n");
        UART1_TxString("MCUID: ");
        for (j = 0; j < 7; j++)
        {
            UART1_TxHex(readCode(18 + j));
            UART1_TxChar(' ');
        }
        UART1_TxString("\r\n");
        UART1_TxString("Current IRCBAND:");
        UART1_TxHex(IRCBAND);
        UART1_TxString(", VRTRIM:");
        UART1_TxHex(VRTRIM);
        UART1_TxString(", IRTRIM:");
        UART1_TxHex(IRTRIM);
        UART1_TxString(", LIRTRIM:");
        UART1_TxHex(LIRTRIM);
        UART1_TxString("\r\n\r\n");
 
        SYS_Delay(50);
    }
}

readCode()

uint8_t readCode

(

uint8_t

offset

)

Scan to find most close VRTRIM and IRTRIM for specified frequency.

Change build_flags in platformio.ini D__CONF_FOSC -> target frequency, e.g. 36864000UL D__CONF_MCU_MODEL -> MCU type, e.g. MCU_MODEL_STC8H3K64S2 D__CONF_IRCBAND -> frequency band depending on the frequency STC8H1K - 00:20MHz, 01:35MHz STC8H3K,STC8H8K - 02:24MHz, 03:40MHz

Connect UART at baud 115200 and read output, when the output is not garbled, find the middle value of VRTRIM and IRTRIM, lower VRTRIM is preferred

Definition at line 31 of file clock_trim_scan.c.

{
    return (*(unsigned char volatile __CODE *)(__CID_ADDR + offset));
}