Arduino ATmega 328 Emulator

Debugging the I2C registers is a bit more chalenging than the other periferals.

USART without the RX part, now works. Messages are printed to the terminal window.

This is the Arduino code I used for the sketch.

 void setup() {
   Serial.begin(9600); 
 }
 
 void loop() {
   Serial.print("Test UART Message " );
   Serial.println("0123456789");
   
   delay(2);                     
 }

IRQ USART, UDRE "__vector_19" is responsible for writing out the TX buffer to I/O 0xC6

"_ZN5Print5printEPKc" Is the subroutine that gets called to update the TX buffer.

Register 0x88 OCR1AL and 0x89 OCR1AH comtrols the PWM duty rate.

I finally got the blink sketch running.

To get the blink sketch up and running in the Emulator, I had to get the CPU, Memory Mapper, GPIOs, and the timer overflow/compare IRQs working.

The IRQ and "micros" function use SRAM 0x0007~0x000A as a 32bit timer.

After all that fun stuff, I had an alternating bit in the PORTB register.