Apple-2-Tools/izapple2
1
0
Fork 0
mirror of https://github.com/ivanizag/izapple2.git synced 2024-12-22 09:30:19 +00:00
Code Issues Projects Releases Wiki Activity

Support for stack instructions PHA, PHP, PLA and PLP

Browse Source
This commit is contained in:
Ivan Izaguirre 2019-02-02 22:53:26 +01:00
parent 1c1bd79f13
commit e43a0a9ae1
2 changed files with 64 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
execute.go
View File

@ -247,6 +247,26 @@ func buildOpSub(addressMode int) opFunc {
}
}
const stackAddress uint16 = 0x0100
func buildOpPush(reg int) opFunc {
return func(s *state, line []uint8, opcode opcode) {
value := s.registers.getRegister(reg)
adresss := stackAddress + uint16(s.registers.getSP())
s.memory[adresss] = value
s.registers.setSP(s.registers.getSP() - 1)
}
}
func buildOpPull(reg int) opFunc {
return func(s *state, line []uint8, opcode opcode) {
s.registers.setSP(s.registers.getSP() + 1)
adresss := stackAddress + uint16(s.registers.getSP())
value := s.memory[adresss]
s.registers.setRegister(reg, value)
}
}
/*
TODO:
http://www.6502.org/tutorials/decimal_mode.html
@ -258,14 +278,14 @@ JSR
RTI
RTS
PHA
PHP
PLA
PLP
*/
var opcodes = [256]opcode{
0x48: opcode{"PHA", 1, 3, buildOpPush(regA)},
0x08: opcode{"PHP", 1, 3, buildOpPush(regP)},
0x68: opcode{"PLA", 1, 4, buildOpPull(regA)},
0x28: opcode{"PLP", 1, 4, buildOpPull(regP)},
0x09: opcode{"ORA", 2, 2, buildOpLogic(modeImmediate, operationOr)},
0x05: opcode{"ORA", 2, 3, buildOpLogic(modeZeroPage, operationOr)},
0x15: opcode{"ORA", 2, 4, buildOpLogic(modeZeroPageX, operationOr)},

39
execute_test.go
View File

@ -408,3 +408,42 @@ func TestBranch(t *testing.T) {
t.Errorf("Error in BCC, %v", s.registers)
}
}
func TestStack(t *testing.T) {
var s state
s.registers.setSP(0xF0)
s.registers.setA(0xA0)
s.registers.setP(0x0A)
executeLine(&s, []uint8{0x48})
if s.registers.getSP() != 0xEF {
t.Errorf("Error in PHA stack pointer, %v", s.registers)
}
if s.memory[0x01F0] != 0xA0 {
t.Errorf("Error in PHA, %v", s.registers)
}
executeLine(&s, []uint8{0x08})
if s.registers.getSP() != 0xEE {
t.Errorf("Error in PHP stack pointer, %v", s.registers)
}
if s.memory[0x01EF] != 0x0A {
t.Errorf("Error in PHP, %v", s.registers)
}
executeLine(&s, []uint8{0x68})
if s.registers.getSP() != 0xEF {
t.Errorf("Error in PLA stack pointer, %v", s.registers)
}
if s.registers.getA() != 0x0A {
t.Errorf("Error in PLA, %v", s.registers)
}
executeLine(&s, []uint8{0x28})
if s.registers.getSP() != 0xF0 {
t.Errorf("Error in PLP stack pointer, %v", s.registers)
}
if s.registers.getP() != 0xA0 {
t.Errorf("Error in PLP, %v", s.registers)
}
}