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Handle the virtual bits 5 and 4 when pushing P to the stack

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This commit is contained in:
Ivan Izaguirre 2019-02-03 01:38:36 +01:00
parent 7f9aea24e9
commit 2b02b8de9e
3 changed files with 16 additions and 11 deletions
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20
execute.go
View File

@ -274,18 +274,20 @@ func pullWord(s *state) uint16 {
}
func buildOpPush(reg int) opFunc {
return func(s *state, line []uint8, opcode opcode) {
pushByte(s, s.registers.getRegister(reg))
}
}
func buildOpPull(reg int) opFunc {
return func(s *state, line []uint8, opcode opcode) {
s.registers.setRegister(reg, pullByte(s))
}
}
func opPHA(s *state, line []uint8, opcode opcode) {
pushByte(s, s.registers.getA())
}
func opPHP(s *state, line []uint8, opcode opcode) {
pushByte(s, s.registers.getP()|(flagB+flag5))
}
func buildOpJump(addressMode int) opFunc {
return func(s *state, line []uint8, opcode opcode) {
_, address, _ := resolveWithAddressMode(s, line, addressMode)
@ -312,7 +314,7 @@ func opRTS(s *state, line []uint8, opcode opcode) {
func opBRK(s *state, line []uint8, opcode opcode) {
s.registers.setFlag(flagI)
pushWord(s, s.registers.getPC()+1) // TODO: De we have to add 1 or 2?
pushByte(s, s.registers.getP())
pushByte(s, s.registers.getP()|(flagB+flag5))
s.registers.setPC(s.memory.getWord(0xFFFE))
}
@ -324,8 +326,8 @@ var opcodes = [256]opcode{
0x40: opcode{"RTI", 1, 6, opRTI},
0x60: opcode{"RTS", 1, 6, opRTS},
0x48: opcode{"PHA", 1, 3, buildOpPush(regA)},
0x08: opcode{"PHP", 1, 3, buildOpPush(regP)},
0x48: opcode{"PHA", 1, 3, opPHA},
0x08: opcode{"PHP", 1, 3, opPHP},
0x68: opcode{"PLA", 1, 4, buildOpPull(regA)},
0x28: opcode{"PLP", 1, 4, buildOpPull(regP)},

6
execute_test.go
View File

@ -427,7 +427,7 @@ func TestStack(t *testing.T) {
if s.registers.getSP() != 0xEE {
t.Errorf("Error in PHP stack pointer, %v", s.registers)
}
if s.memory[0x01EF] != 0x0A {
if s.memory[0x01EF] != 0x3A {
t.Errorf("Error in PHP, %v", s.registers)
}
@ -435,7 +435,7 @@ func TestStack(t *testing.T) {
if s.registers.getSP() != 0xEF {
t.Errorf("Error in PLA stack pointer, %v", s.registers)
}
if s.registers.getA() != 0x0A {
if s.registers.getA() != 0x3A {
t.Errorf("Error in PLA, %v", s.registers)
}
@ -447,3 +447,5 @@ func TestStack(t *testing.T) {
t.Errorf("Error in PLP, %v", s.registers)
}
}
// TODO: Tests for BRK, JMP, JSR, RTI, RTS

1
registers.go
View File

@ -15,6 +15,7 @@ const (
const (
flagN uint8 = 1 << 7
flagV uint8 = 1 << 6
flag5 uint8 = 1 << 5
flagB uint8 = 1 << 4
flagD uint8 = 1 << 3
flagI uint8 = 1 << 2