6502/mre-mos6502
1
0
Fork 0
mirror of https://github.com/mre/mos6502.git synced 2024-11-28 07:49:19 +00:00
Code Issues Projects Releases Wiki Activity

don't overshoot the stack pointer! (pla and plp)

Browse Source
This commit is contained in:
Sam M W 2023-04-15 21:37:47 +01:00
parent 62424070a1
commit 26a2f51bc6
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
src/cpu.rs
View File

@ -433,13 +433,13 @@ impl<M: Bus> CPU<M> {
(Instruction::PLA, OpInput::UseImplied) => { (Instruction::PLA, OpInput::UseImplied) => {
// Pull accumulator // Pull accumulator
self.pull_from_stack(); self.pull_from_stack();
let val: u8 = self.pull_from_stack(); let val: u8 = self.fetch_from_stack();
self.registers.accumulator = val as i8; self.registers.accumulator = val as i8;
} }
(Instruction::PLP, OpInput::UseImplied) => { (Instruction::PLP, OpInput::UseImplied) => {
// Pull status // Pull status
self.pull_from_stack(); self.pull_from_stack();
let val: u8 = self.pull_from_stack(); let val: u8 = self.fetch_from_stack();
// The `truncate` here won't do anything because we have a // The `truncate` here won't do anything because we have a
// constant for the single unused flags bit. This probably // constant for the single unused flags bit. This probably
// corresponds to the behavior of the 6502...? FIXME: verify // corresponds to the behavior of the 6502...? FIXME: verify