first public release

ldi_ldir_tests.go

@@ -0,0 +1,43 @@
+package z80
+
+import "testing"
+
+// LDI/LDDR/LDIR correctness: registers, memory effects, PV from BC!=0, and timing totals.
+func TestLDI_Registers_Flags_Memory(t *testing.T) {
+	cpu, mem, _ := testCPU()
+	cpu.SetHL(0x4000)
+	cpu.SetDE(0x4100)
+	cpu.SetBC(3)
+	mem.WriteByte(0x4000, 0x11)
+	loadProgram(cpu, mem, 0x0000, 0xED, 0xA0) // LDI
+	c := mustStep(t, cpu)
+	assertEq(t, c, 16, "LDI cycles")
+	assertEq(t, mem.ReadByte(0x4100), byte(0x11), "LDI moved byte")
+	assertEq(t, cpu.GetHL(), uint16(0x4001), "HL++")
+	assertEq(t, cpu.GetDE(), uint16(0x4101), "DE++")
+	assertEq(t, cpu.GetBC(), uint16(2), "BC--")
+	assertFlag(t, cpu, FLAG_N, false, "N cleared")
+	assertFlag(t, cpu, FLAG_H, false, "H cleared")
+	assertFlag(t, cpu, FLAG_PV, true, "PV mirrors BC!=0")
+
+	// LDIR for 2 bytes: expect 21 + 16 = 37 cycles and final regs.
+	cpu, mem, _ = testCPU()
+	cpu.SetHL(0x5000)
+	cpu.SetDE(0x6000)
+	cpu.SetBC(2)
+	mem.WriteByte(0x5000, 0xAA)
+	mem.WriteByte(0x5001, 0xBB)
+	loadProgram(cpu, mem, 0x0000, 0xED, 0xB0) // LDIR
+	total := 0
+	for {
+		total += mustStep(t, cpu)
+		if cpu.GetBC() == 0 {
+			break
+		}
+	}
+	assertEq(t, total, 37, "LDIR total cycles for 2 bytes")
+	assertEq(t, mem.ReadByte(0x6000), byte(0xAA), "LDIR first byte")
+	assertEq(t, mem.ReadByte(0x6001), byte(0xBB), "LDIR second byte")
+	assertEq(t, cpu.GetHL(), uint16(0x5002), "HL end")
+	assertEq(t, cpu.GetDE(), uint16(0x6002), "DE end")
+}