Arduino ATmega 328 Emulator

Details

I built this cause I wanted a emulator for the Arduino UNO, not a simulator that doesn't tell me why and where thing crash. I've semi bricked many Arduino units, but always got them back up and running with another UNO. With this emulator, I can properly debug my system step by step, see the registers/memory, and see when memory writes go out of bounds.

For decoding the opcodes, I used a vector table of 65536 entries.

There are 107 opcode groups, 131 total instruction variants.

Right now I have 90 more opcodes to complete.

This emulator will be cycle accurate, support virtual GPIO, and console printing.

For the moment, I'm skipping working with the boot loaders, but it's a option for the future.

Project Logs

Collapse

I2C function in progress.
tehaxor69 • 05/09/2017 at 00:37 • 0 comments

Debugging the I2C registers is a bit more chalenging than the other periferals.
USART with printing now working.
tehaxor69 • 04/26/2017 at 21:38 • 0 comments
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.
Fade Sketch + PWM now working.
tehaxor69 • 04/25/2017 at 22:54 • 0 comments

Register 0x88 OCR1AL and 0x89 OCR1AH comtrols the PWM duty rate.
Blink sketch is now working.
tehaxor69 • 04/22/2017 at 23:51 • 0 comments

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.