gb-player/gb/cpu_test.go

170 lines
3.6 KiB
Go

package gb
import (
"testing"
"github.com/stretchr/testify/assert"
)
func createCPU(data []byte) *CPU {
cart := Cartridge{Filename: "test"}
cart.Data = data
cpu := NewCPU(NewBus(&cart))
cpu.Regs.PC = 0
return cpu
}
func TestSetFlag(t *testing.T) {
cartridge, _ := InsertCartridge("../roms/dmg-acid2.gb")
bus := NewBus(cartridge)
cpu := NewCPU(bus)
cpu.SetFlag(C)
assert.True(t, cpu.IsFlagSet(C))
}
func TestClearFlag(t *testing.T) {
cartridge, _ := InsertCartridge("../roms/dmg-acid2.gb")
bus := NewBus(cartridge)
cpu := NewCPU(bus)
cpu.SetFlag(C)
assert.True(t, cpu.IsFlagSet(C))
cpu.ClearFlag(C)
assert.False(t, cpu.IsFlagSet(C))
}
func TestToggleFlag(t *testing.T) {
cartridge, _ := InsertCartridge("../roms/dmg-acid2.gb")
bus := NewBus(cartridge)
cpu := NewCPU(bus)
cpu.ToggleFlag(C)
assert.True(t, cpu.IsFlagSet(C))
cpu.ToggleFlag(C)
assert.False(t, cpu.IsFlagSet(C))
}
func TestInstruction00(t *testing.T) {
cpu := createCPU([]byte{0x00, 0x00, 0x00})
cpu.Step()
assert.Equal(t, uint16(0x01), cpu.Regs.PC)
}
func TestInstruction3C(t *testing.T) {
// Should increment A register
cpu := createCPU([]byte{0x3C, 0x00, 0x00})
assert.Equal(t, byte(0x0), cpu.Regs.A)
cpu.Step()
assert.Equal(t, byte(0x01), cpu.Regs.A)
// Should clear Zero Flag
cpu = createCPU([]byte{0x3C, 0x00, 0x00})
cpu.SetFlag(Z)
cpu.Step()
assert.False(t, cpu.IsFlagSet(Z))
// Should set Zero Flag
cpu = createCPU([]byte{0x3C, 0x00, 0x00})
cpu.Regs.A = 0xFF
assert.False(t, cpu.IsFlagSet(Z))
cpu.Step()
assert.True(t, cpu.IsFlagSet(Z))
// Should clear Subtract Flag
cpu = createCPU([]byte{0x3C, 0x00, 0x00})
cpu.SetFlag(N)
cpu.Step()
assert.False(t, cpu.IsFlagSet(N))
// Should set Half Carry Flag if we overflow from bit 3
cpu = createCPU([]byte{0x3C, 0x00, 0x00})
cpu.Regs.A = 0x0F
assert.False(t, cpu.IsFlagSet(H))
cpu.Step()
assert.True(t, cpu.IsFlagSet(H))
// Should clear Half Carry Flag if we don't overflow from bit 3
cpu = createCPU([]byte{0x3C, 0x00, 0x00})
cpu.SetFlag(H)
cpu.Step()
assert.False(t, cpu.IsFlagSet(H))
}
func TestInstructionC3(t *testing.T) {
cpu := createCPU([]byte{0xC3, 0x50, 0x01})
cpu.Step()
assert.Equal(t, uint16(0x150), cpu.Regs.PC)
}
func TestInstructionE9(t *testing.T) {
cpu := createCPU([]byte{0xE9, 0x00, 0x00})
cpu.Regs.H = 0x12
cpu.Regs.L = 0x34
cpu.Step()
assert.Equal(t, uint16(0x1234), cpu.Regs.PC)
}
func TestInstructionF3(t *testing.T) {
cpu := createCPU([]byte{0xF3, 0x00, 0x00})
cpu.InterruptMasterEnable = true
cpu.Step()
assert.False(t, cpu.InterruptMasterEnable)
}
func TestInstruction31(t *testing.T) {
cpu := createCPU([]byte{0x31, 0xFF, 0xCF})
cpu.Step()
// Should load SP with n16 value
assert.Equal(t, uint16(0xCFFF), cpu.Regs.SP)
// Should step over the 16 bit value onto the next instruction, i.e. increase the program counter with 3.
assert.Equal(t, uint16(0x0003), cpu.Regs.PC)
}
func TestInstructionCD(t *testing.T) {
cpu := createCPU([]byte{0xCD, 0x4C, 0x48, 0x41})
cpu.Step()
// Should push the address of the next instruction onto the stack
// In this case 0x41 which is at address 0x03 (i.e. the 4th instruction in the row above creating the CPU instance)
assert.Equal(t, uint16(0x03), cpu.Bus.Read16(cpu.Regs.SP))
// Should jump to n16 value
assert.Equal(t, uint16(0x484C), cpu.Regs.PC)
}
func TestInstruction21(t *testing.T) {
cpu := createCPU([]byte{0x21, 0x34, 0x12})
cpu.Step()
// Should load the 16-bit immediate value into the combined HL register
assert.Equal(t, byte(0x12), cpu.Regs.H)
assert.Equal(t, byte(0x34), cpu.Regs.L)
// Should increase the stack pointer
assert.Equal(t, uint16(0x3), cpu.Regs.PC)
}