feat: implement avrInterrupt()

used to invoke hardware interrupt

1 files changed, 18 insertions, 0 deletions

diff --git a/src/interrupt.spec.ts b/src/interrupt.spec.ts
new file mode 100644
index 0000000..06979ed
--- /dev/null
+++ b/src/interrupt.spec.ts
@@ -0,0 +1,18 @@
+import { CPU } from './cpu';
+import { avrInterrupt } from './interrupt';
+
+describe('avrInterrupt', () => {
+  it('should execute interrupt handler', () => {
+    const cpu = new CPU(new Uint16Array(0x8000));
+    cpu.pc = 0x520;
+    cpu.data[93] = 0x80; // SP <- 0x80
+    cpu.data[95] = 0b10000001; // SREG <- I------C
+    avrInterrupt(cpu, 5);
+    expect(cpu.cycles).toEqual(2);
+    expect(cpu.pc).toEqual(5);
+    expect(cpu.data[93]).toEqual(0x7e); // SP
+    expect(cpu.data[0x80]).toEqual(0x20); // Return addr low
+    expect(cpu.data[0x7f]).toEqual(0x5); // Return addr high
+    expect(cpu.data[95]).toEqual(0b00000001); // SREG: -------C
+  });
+});