diff options
Diffstat (limited to 'instructions/LSR.ts')
| -rw-r--r-- | instructions/LSR.ts | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/instructions/LSR.ts b/instructions/LSR.ts new file mode 100644 index 0000000..61adadb --- /dev/null +++ b/instructions/LSR.ts @@ -0,0 +1,23 @@ +import type The65c02 from "../65c02.ts"; + +export default function (this: The65c02, mode: string) { + if (mode == 'implicit') { + const mem = this.regA.num(); + const result = mem >> 1; + this.negative = (result & 128) != 0 + this.zero = result == 0 + this.carry = (mem & 1) != 0 + this.regA.set(result & 0xFF); + } else { + const addr = this.getAddr(mode) + this.io.address.set(addr); + this.read() + const mem = this.io.data.num(); + const result = mem >> 1; + this.negative = (result & 128) != 0 + this.zero = result == 0 + this.carry = (mem & 1) != 0 + this.io.data.set(result & 0xFF); + this.write() + } +} \ No newline at end of file |