Commit be61e5a

bench51be61e5a

add jnz, README.md

+27 −2

4 files changed

−Context 3+

A README.md View

M src/cpu.rs View

M src/instructions.rs View

M src/main.rs View

		@@ -153,4 +153,17 @@ impl CPU {
153	153
154	154		}
155	155
	156	+	pub fn jnz(&mut self, mem: &mut Memory) {
	157	+	let low = mem.read(self.pc) as u16; self.inc_pc();
	158	+	let high = mem.read(self.pc) as u16; self.inc_pc();
	159	+
	160	+	let addrs = (high << 8) \| low;
	161	+
	162	+	if !self.zero {
	163	+	self.pc = addrs;
	164	+	}
	165	+
	166	+	}
	167	+
	168	+
156	169		}

		@@ -20,7 +20,7 @@ fn main() {
20	20		// b = 2
21	21		mem.write(0x0003, Instruction::MOV as u8);
22	22		mem.write(0x0004, 1);
23		−	mem.write(0x0005, 5);
	23	+	mem.write(0x0005, 3);
24	24
25	25		// a = a + b
26	26		mem.write(0x0006, Instruction::SUB as u8);
		@@ -28,7 +28,7 @@ fn main() {
28	28		mem.write(0x0008, 1);
29	29
30	30		// JMP to halt
31		−	mem.write(0x0009, Instruction::JZ as u8);
	31	+	mem.write(0x0009, Instruction::JNZ as u8);
32	32		mem.write(0x000a, 0x0f); // Low
33	33		mem.write(0x000b, 0x00); // High
34	34
		@@ -50,6 +50,7 @@ fn main() {
50	50		x if x == Instruction::SUB as u8 => cpu.sub(&mut mem),
51	51		x if x == Instruction::JMP as u8 => cpu.jmp(&mut mem),
52	52		x if x == Instruction::JZ as u8 => cpu.jz(&mut mem),
	53	+	x if x == Instruction::JNZ as u8 => cpu.jnz(&mut mem),
53	54		x if x == Instruction::HLT as u8 => cpu.halt(),
54	55		_ => panic!("Unknown opcode {:02X}", opcode),
55	56		}