From e662916313092382b18676d594bdbb25b5d31682 Mon Sep 17 00:00:00 2001
From: Uri Shaked
Date: Thu, 9 Apr 2020 00:21:02 +0300
Subject: feat(instruction): implement EICALL, EIJMP #31

---
 src/cpu/instruction.spec.ts | 23 +++++++++++++++++++++++
 src/cpu/instruction.ts      | 15 +++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/src/cpu/instruction.spec.ts b/src/cpu/instruction.spec.ts
index 0d0d566..4f6e045 100644
--- a/src/cpu/instruction.spec.ts
+++ b/src/cpu/instruction.spec.ts
@@ -179,6 +179,29 @@ describe('avrInstruction', () => {
     expect(cpu.cycles).toEqual(3);
   });
 
+  it('should execute `EICALL` instruction', () => {
+    cpu = new CPU(new Uint16Array(0x20000));
+    loadProgram('EICALL');
+    cpu.data[94] = 0;
+    cpu.data[93] = 0x80;
+    cpu.data[0x3c] = 1; // EIND <- 1
+    cpu.dataView.setUint16(30, 0x1234, true); // Z <- 0x1234
+    avrInstruction(cpu);
+    expect(cpu.pc).toEqual(0x11234);
+    expect(cpu.cycles).toEqual(4);
+    expect(cpu.data[0x80]).toEqual(1); // Return address
+  });
+
+  it('should execute `EIJMP` instruction', () => {
+    cpu = new CPU(new Uint16Array(0x20000));
+    loadProgram('EIJMP');
+    cpu.data[0x3c] = 1; // EIND <- 1
+    cpu.dataView.setUint16(30, 0x1040, true); // Z <- 0x1040
+    avrInstruction(cpu);
+    expect(cpu.pc).toEqual(0x11040);
+    expect(cpu.cycles).toEqual(2);
+  });
+
   it('should execute `ELPM` instruction', () => {
     cpu = new CPU(new Uint16Array(0x20000));
     loadProgram('ELPM');
diff --git a/src/cpu/instruction.ts b/src/cpu/instruction.ts
index e786bf4..07f1576 100644
--- a/src/cpu/instruction.ts
+++ b/src/cpu/instruction.ts
@@ -209,6 +209,21 @@ export function avrInstruction(cpu: ICPU) {
     sreg |= 128 === value ? 8 : 0;
     sreg |= ((sreg >> 2) & 1) ^ ((sreg >> 3) & 1) ? 0x10 : 0;
     cpu.data[95] = sreg;
+  } else if (opcode === 0x9519) {
+    /* EICALL, 1001 0101 0001 1001 */
+    const retAddr = cpu.pc + 1;
+    const sp = cpu.dataView.getUint16(93, true);
+    const eind = cpu.data[0x3c];
+    cpu.data[sp] = retAddr & 255;
+    cpu.data[sp - 1] = (retAddr >> 8) & 255;
+    cpu.dataView.setUint16(93, sp - 2, true);
+    cpu.pc = ((eind << 16) | cpu.dataView.getUint16(30, true)) - 1;
+    cpu.cycles += 3;
+  } else if (opcode === 0x9419) {
+    /* EIJMP, 1001 0100 0001 1001 */
+    const eind = cpu.data[0x3c];
+    cpu.pc = ((eind << 16) | cpu.dataView.getUint16(30, true)) - 1;
+    cpu.cycles++;
   } else if (opcode === 0x95d8) {
     /* ELPM, 1001 0101 1101 1000 */
     const rampz = cpu.data[0x3b];
-- 
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