Dear Community Members,
I recently started my venture with STM8S Micro-controller. I bought an STM8S103F3P6 Chip.
The very first thing i want to understand is Clock Control of the MCU.
Therefore i set the MCU to HSE 16MHz. Although I wanted to see if it really is working on 16MHz, I decided to use the controller's clock output capability.
Here's my main code:
#include <stdint.h>
#include "stm8s_system.h"
#include "delay.h"
#define F_CPU 16000000UL
#define RED_LED_PIN 4
#define GREEN_LED_PIN 6
#define BLUE_LED_PIN 5
#define DEBUG_PIN 3
#define CLOCK_OUTPUT_PIN 4
void main()
{
PORTC_DDR|=(1<<CLOCK_OUTPUT_PIN);
PORTC_CR1|=(1<<CLOCK_OUTPUT_PIN);
PORTC_CR2|=(1<<CLOCK_OUTPUT_PIN);
PORTC_DDR|=(1<<DEBUG_PIN);
PORTC_CR1|=(1<<DEBUG_PIN);
PORTC_CR2|=(1<<DEBUG_PIN);
CLK_CCOR|=0x08;
CLK_CCOR|=0x01;
System_Clock_Init_External();
PORTD_DDR|=(1<<GREEN_LED_PIN);
PORTD_CR1|=(1<<GREEN_LED_PIN);
PORTD_CR2|=(1<<GREEN_LED_PIN);
while(1)
{
TOGGLE_PIN(PORTD_ODR,GREEN_LED_PIN);
TOGGLE_PIN(PORTC_ODR,DEBUG_PIN);
delay_ms(20);
}
}
Here's how i am accessing registers:
#define OFFSET_ADDRESS 0x5000
#define SFR(addr) (*(volatile unsigned char *)(OFFSET_ADDRESS + (addr)))
#define PORTC_ODR SFR(0x0A)
#define PORTC_IDR SFR(0x0B)
#define PORTC_DDR SFR(0x0C)
#define PORTC_CR1 SFR(0x0D)
#define PORTC_CR2 SFR(0x0E)
#define CLK_ICKR SFR(0xC0)
#define CLK_ECKR SFR(0xC1)
#define CLK_CMSR SFR(0xC3)
#define CLK_SWR SFR(0xC4)
#define CLK_SWCR SFR(0xC5)
#define CLK_CKDIVR aSFR(0xC6)
#define CLK_PCKENR1 SFR(0xC7)
#define CLK_CSSR SFR(0xC8)
#define CLK_CCOR SFR(0xC9)
#define CLK_PCKENR2 SFR(0xCA)
#define CLK_HSITRIMR SFR(0xCC)
#define CLK_SWIMCCR SFR(0xCD)
Here's my external clock init function:
void System_Clock_Init_External(void)
{
CLEAR_REGISTER(CLK_ICKR,0xFF);
SET_BIT_IN_REGISTER(CLK_ECKR,0);
while(!(READ_REGISTER_BIT(CLK_ECKR,1)));
CLEAR_REGISTER(CLK_CKDIVR,0xFF);
SET_REGISTER(CLK_PCKENR1,0xFF);
SET_REGISTER(CLK_PCKENR2,0xFF);
//CLEAR_REGISTER(CLK_CCOR,0xFF);
CLEAR_REGISTER(CLK_HSITRIMR,0xFF);
CLEAR_REGISTER(CLK_SWIMCCR,0xFF);
CLEAR_REGISTER(CLK_SWCR,0xFF);
SET_REGISTER(CLK_SWR,0xB4);
SET_BIT_IN_REGISTER(CLK_SWCR,1);
while((READ_REGISTER_BIT(CLK_SWCR,0)));
}
When i check the output on pin PC4 on an Oscilloscope, all i get 1.4V DC Voltage.
What is it that i am missing?
