fabs/oboy
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Add CPU instructions.

Browse source
This commit is contained in:
Fabien Freling 2015-06-15 00:52:50 +02:00
parent 6599857947
commit b52a070087
1 changed files with 33 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

43
src/cpu.ml
View file

@ -76,7 +76,7 @@ let update_flag_reg cpu =
cpu.reg.f <- char_of_int @@ z + n + h + c
let inc_pc cpu count =
cpu.reg.pc <- cpu.reg.pc + count
cpu.reg.pc <- (cpu.reg.pc + count) mod 0xFFFF
let inc_cycles cpu count =
cpu.cycles <- cpu.cycles + count
@ -118,6 +118,14 @@ let read_pc_2bytes cpu mem =
inc_pc cpu 2;
word
let pop_stack cpu mem =
let low = Memory.get mem cpu.reg.sp in
cpu.reg.sp <- (cpu.reg.sp + 1) mod 0xFFFF;
let high = Memory.get mem cpu.reg.sp in
cpu.reg.sp <- (cpu.reg.sp + 1) mod 0xFFFF;
merge_bytes low high
(**
http://imrannazar.com/GameBoy-Z80-Opcode-Map
@ -135,12 +143,35 @@ let run cpu (mem: Memory.map) =
| '\x7E' -> printf " LD \tA, (HL)\n";
let hl = merge_bytes cpu.reg.l cpu.reg.h in
cpu.reg.a <- Memory.get mem hl;
inc_cycles cpu 8;
inc_cycles cpu 8
| '\x36' -> let n = read_pc_byte cpu mem in
printf " LD \t(HL) 0x%02X\n" n;
let hl = merge_bytes cpu.reg.l cpu.reg.h in
Memory.set mem hl (char_of_int n);
inc_cycles cpu 12
(* CPU control *)
| '\x00' -> printf " NOP\n";
inc_cycles cpu 4
(* jump *)
| '\xC9' -> printf " RET\n";
cpu.reg.pc <- pop_stack cpu mem;
inc_cycles cpu 16
| '\xC0' -> printf " RET \tNZ\n";
if cpu.flag.z = false then
begin
cpu.reg.pc <- pop_stack cpu mem;
inc_cycles cpu 20
end else
inc_cycles cpu 8
| '\x03' -> printf " INC \tBC\n";
inc_BC cpu;
inc_cycles cpu 8
@ -218,14 +249,6 @@ let run cpu (mem: Memory.map) =
cpu.reg.a <- char_of_int @@ int_A lxor int_A;
inc_cycles cpu 4
| '\xC0' -> printf " RET \tNZ\n";
if cpu.flag.z = false then
begin
cpu.reg.pc <- cpu.reg.sp;
inc_cycles cpu 20
end else
inc_cycles cpu 8
| '\xC3' -> let addr = read_pc_2bytes cpu mem in
printf " JP \t0x%04X\n" addr;
cpu.reg.pc <- addr; inc_cycles cpu 16