Awesome
Game Boy Opcodes
Game Boy CPU (Sharp LR35902) instruction set (opcodes)
The opcodes.json contains a JSON representation of the complete Sharp LR35902 instruction set. Inside the bin
folder you will find the script used to generate the opcodes.json
file from the pastraiser.com site.
Description of opcodes.json
The opcodes.json file includes some minor fixes in the opcode length and timings not present on the pastraiser.com site.
{
"unprefixed": {
"0xc0": { <-- Address
"mnemonic": "SET", <-- Instruction mnemonic
"length": 2, <-- Length in bytes
"cycles": [ <-- Duration in cycles
8
],
"flags": [ <-- Flags affected
"-", <-- Z - Zero Flag
"-", <-- N - Subtract Flag
"-", <-- H - Half Carry Flag
"-" <-- C - Carry Flag
],
"addr": "0xc0", <-- Address
"group": "control/misc" <-- Opcode group
"operand1": "0", <-- Operand 1
"operand2": "B" <-- Operand 2
},
...
},
...
}
Operation group table:
op group | description |
---|---|
x8/lsm | 8-bit Load/Store/Move |
x16/lsm | 16-bit Load/Store/Move |
x8/alu | 8-bit Arithmetic Logic Unit |
x16/alu | 16-bit Arithmetic Logic Unit |
x8/rsb | 8-bit ??? |
control/br | branch |
control/misc | misc |
Reference documentation
http://www.pastraiser.com/cpu/gameboy/gameboy_opcodes.html
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/lmmendes/game-boy-opcodes. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
License
The code is available as open source under the terms of the MIT License.