feat: initial implementation of USART

#6

4 files changed, 19 insertions, 1 deletions

diff --git a/demo/src/execute.ts b/demo/src/execute.ts
index 4568839..f2c7d82 100644
--- a/demo/src/execute.ts
+++ b/demo/src/execute.ts
@@ -4,9 +4,11 @@ import {
   CPU,
   timer0Config,
   AVRIOPort,
+  AVRUSART,
   portBConfig,
   portCConfig,
-  portDConfig
+  portDConfig,
+  usart0Config
 } from 'avr8js';
 import { loadHex } from './intelhex';
 
@@ -20,6 +22,8 @@ export class AVRRunner {
   readonly portB: AVRIOPort;
   readonly portC: AVRIOPort;
   readonly portD: AVRIOPort;
+  readonly usart: AVRUSART;
+  readonly speed = 16e6; // 16 MHZ
 
   private stopped = false;
 
@@ -30,6 +34,7 @@ export class AVRRunner {
     this.portB = new AVRIOPort(this.cpu, portBConfig);
     this.portC = new AVRIOPort(this.cpu, portCConfig);
     this.portD = new AVRIOPort(this.cpu, portDConfig);
+    this.usart = new AVRUSART(this.cpu, usart0Config, this.speed);
   }
 
   async execute(callback: (cpu: CPU) => void) {
@@ -37,6 +42,7 @@ export class AVRRunner {
     for (;;) {
       avrInstruction(this.cpu);
       this.timer.tick();
+      this.usart.tick();
       if (this.cpu.cycles % 50000 === 0) {
         callback(this.cpu);
         await new Promise((resolve) => setTimeout(resolve, 0));
diff --git a/demo/src/index.css b/demo/src/index.css
index a3fa8b8..6801204 100644
--- a/demo/src/index.css
+++ b/demo/src/index.css
@@ -46,3 +46,7 @@ body {
   margin: 0;
   white-space: pre-line;
 }
+
+#serial-output-text {
+  color: blue;
+}
diff --git a/demo/src/index.html b/demo/src/index.html
index 935bcff..2a8e924 100644
--- a/demo/src/index.html
+++ b/demo/src/index.html
@@ -20,6 +20,7 @@
       <div class="code-editor"></div>
       <div class="compiler-output">
         <pre id="compiler-output-text"></pre>
+        <pre id="serial-output-text"></pre>
       </div>
     </div>
     <script src="//cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.18.0/min/vs/loader.js"></script>
diff --git a/demo/src/index.ts b/demo/src/index.ts
index e51cbbc..7b6f9b1 100644
--- a/demo/src/index.ts
+++ b/demo/src/index.ts
@@ -10,10 +10,12 @@ const BLINK_CODE = `
 // Red LED connected to pin 12. Enjoy!
 
 void setup() {
+  Serial.begin(115200);
   pinMode(LED_BUILTIN, OUTPUT);
 }
 
 void loop() {
+  Serial.println("Blink");
   digitalWrite(LED_BUILTIN, HIGH);
   delay(500);
   digitalWrite(LED_BUILTIN, LOW);
@@ -50,6 +52,7 @@ const stopButton = document.querySelector('#stop-button');
 stopButton.addEventListener('click', stopCode);
 const statusLabel = document.querySelector('#status-label');
 const compilerOutputText = document.querySelector('#compiler-output-text');
+const serialOutputText = document.querySelector('#serial-output-text');
 
 function executeProgram(hex: string) {
   runner = new AVRRunner(hex);
@@ -62,6 +65,9 @@ function executeProgram(hex: string) {
     led12.value = value & D12bit ? true : false;
     led13.value = value & D13bit ? true : false;
   });
+  runner.usart.onByteTransmit = (value) => {
+    serialOutputText.textContent += String.fromCharCode(value);
+  };
   runner.execute((cpu) => {
     const time = formatTime(cpu.cycles / MHZ);
     statusLabel.textContent = 'Simulation time: ' + time;
@@ -73,6 +79,7 @@ async function compileAndRun() {
   led13.value = false;
 
   runButton.setAttribute('disabled', '1');
+  serialOutputText.textContent = '';
   try {
     statusLabel.textContent = 'Compiling...';
     const result = await buildHex(editor.getModel().getValue());