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Doc: Added mnemonics for two opcode constants

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      doc/terminology.org

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@ -7,7 +7,7 @@ GameBoy terminology.
** Terminology
*** Hardware
*** Hardware [[#references][(1)]][[#references][(2)]]
| Name | Modern equivalent | Description |
|-----------------+-------------------+-------------------------------------------|
@ -28,18 +28,20 @@ We start counting from the right as bit *#0*!
*** Opcode
| Name | Bits | Sign | Mnemonics | [[https://gbdev.io/gb-opcodes/optables/][1]] | [[https://rgbds.gbdev.io/docs/v0.5.2/gbz80.7/][2]] | [[https://gekkio.fi/files/gb-docs/gbctr.pdf][3]]/[[http://marc.rawer.de/Gameboy/Docs/GBCPUman.pdf][3]] | [[https://gbdev.io/pandocs/CPU_Instruction_Set.html][4]] | Description | Note |
|-----------+------+----------+-----------+------+-----+------+-----+------------------------------+-------------------|
| | | | | <r> | <r> | <r> | <r> | | |
| immediate | 8 | unsigned | i8 | d8 | n8 | n | | Next byte in memory | |
| immediate | 16 | unsigned | i16 | d16 | n16 | nn | | Next byte in memory | little-endian |
| register | 8 | unsigned | r8 | | r8 | r | | Any of the registers | |
| register | 16 | unsigned | r16 | | r16 | rr | | Any of the registers | little-endian |
| address | 8 | unsigned | a8 | | | (n) | | Address at value | |
| address | 16 | unsigned | a16 or () | a16 | n16 | (nn) | nn | Address at value | little-endian |
| immediate | 8 | signed | s8 | r8 | e8 | e | dd | Next byte in memory | |
| immediate | 8 | unsigned | io8 | (a8) | n16 | (n) | n | 0xff00 + next byte in memory | write to I/O-port |
| condition | | | <ZNHC> | NZ | cc | | f | Execute if condition met | |
| Name | Bits | Sign | Mnemonics | [[https://gbdev.io/gb-opcodes/optables/][1]] | [[https://rgbds.gbdev.io/docs/v0.5.2/gbz80.7/][2]] | [[https://gekkio.fi/files/gb-docs/gbctr.pdf][3]]/[[http://marc.rawer.de/Gameboy/Docs/GBCPUman.pdf][3]] | [[https://gbdev.io/pandocs/CPU_Instruction_Set.html][4]] | Description | Note |
|-----------+------+----------+-----------+------+-----+------+-----+------------------------------+------------------------|
| | | | | <r> | <r> | <r> | <r> | | |
| immediate | 8 | unsigned | i8 | d8 | n8 | n | | Next byte in memory | |
| immediate | 16 | unsigned | i16 | d16 | n16 | nn | | Next byte in memory | little-endian |
| register | 8 | unsigned | r8 | | r8 | r | | Any of the registers | |
| register | 16 | unsigned | r16 | | r16 | rr | | Any of the registers | little-endian |
| address | 8 | unsigned | a8 | | | (n) | | Address at value | |
| address | 16 | unsigned | a16 or () | a16 | n16 | (nn) | nn | Address at value | little-endian |
| immediate | 8 | signed | s8 | r8 | e8 | e | dd | Next byte in memory | used as offset |
| immediate | 8 | unsigned | io8 | (a8) | n16 | (n) | n | 0xff00 + next byte in memory | write to I/O-port |
| condition | | | <ZNHC> | | cc | | f | Execute if condition met | |
| constant | 8 | unsigned | b | | u3 | b | n | Single bit at position 'x' | |
| constant | 8 | unsigned | vec | | vec | | n | One of RST vectors | absolute fixed address |
d = data \\
n = constant
@ -47,14 +49,19 @@ n = constant
**** Flag conditions
Flag conditions, sometimes referred to as ~cc~, are the state the flags need to
be in to execute the opcode. There are four possible checks[[#references][(4)]]:
be in to execute the opcode. There are four possible checks[[#references][(4)]][[#references][(5)]]:
| Code | Meaning | State |
|------+---------------------+-------|
| C | Carry flag is set | 1 |
| NC | Carry flag is unset | 0 |
| Z | Zero flag is set | 1 |
| NZ | Zero flag is unset | 0 |
| Code | Meaning | State |
|------+--------------------------------+-------|
| Z | Execute if Zero flag is set | 1 |
| NZ | Execute if Zero flag is unset | 0 |
| C | Execute if Carry flag is set | 1 |
| NC | Execute if Carry flag is unset | 0 |
**** RST vectors
Absolute fixed address, possible values are[[#references][(4)]]: ~0x00~, ~0x08~, ~0x10~, ~0x18~,
~0x20~, ~0x28~, ~0x30~, and ~0x38~.
*** Variables
@ -68,7 +75,8 @@ be in to execute the opcode. There are four possible checks[[#references][(4)]]:
** References
1. https://gbdev.io/pandocs/Memory_Map.html
2. https://gbdev.io/pandocs/Specifications.html
1. [[https://gbdev.io/pandocs/Memory_Map.html]["Memory Map"]]. rgbdev.io. Retrieved 22 Aug 2022.
2. [[https://gbdev.io/pandocs/Specifications.html]["Specifications"]]. rgbdev.io. Retrieved 22 Aug 2022.
3. [[https://robdor.com/2016/08/10/gameboy-emulator-half-carry-flag/]["A Visual Guide to the Gameboy's Half-Carry Flag"]]. robdor.com. Retrieved 24 Aug 2022.
4. [[http://www.devrs.com/gb/files/opcodes.html]["GameBoy Opcode Summary"]]. devrs.com. Retrieved 25 Aug 2022.
4. [[https://rgbds.gbdev.io/docs/v0.5.2/gbz80.7#LEGEND]["gbz80(7) — CPU opcode reference"]]. rgbds.gbdev.io. Retrieved 26 Aug 2022.
5. [[http://www.devrs.com/gb/files/opcodes.html]["GameBoy Opcode Summary"]]. devrs.com. Retrieved 25 Aug 2022.

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