shithub: rgbds

ref: f1f314270d814a13a56f7cf84dee68a81ac79d88
dir: /src/gbz80.7/

.\"
.\" This file is part of RGBDS.
.\"
.\" Copyright (c) 2017-2018, Antonio Nino Diaz and RGBDS contributors.
.\"
.\" SPDX-License-Identifier: MIT
.\"
.Dd February 23, 2018
.Dt GBZ80 7
.Os
.Sh NAME
.Nm gbz80
.Nd CPU opcode reference
.Sh DESCRIPTION
This is the list of opcodes supported by
.Xr rgbasm 1 ,
including a short description, the number of bytes needed to encode them and the number of CPU cycles at 1MHz (or 2MHz in GBC dual speed mode) needed to complete them.
.Pp
Note: All arithmetic/logic operations that use register
.Sy A
as destination can omit the destination as it is assumed it's register
.Sy A .
The following two lines have the same effect:
.Pp
.Bd -literal -offset indent
OR A,B
OR B
.Ed
.Pp
.Sh LEGEND
List of abbreviations used in this document.
.Bl -tag
.It Ar r8
Any of the 8-bit registers
.Pq Sy A , B , C , D , E , H , L .
.It Ar r16
Any of the general-purpose 16-bit registers
.Pq Sy BC , DE , HL .
.It Ar n8
8-bit integer constant.
.It Ar n16
16-bit integer constant.
.It Ar e8
8-bit offset
.Po Fl Sy 128
to
.Sy 127
.Pc .
.It Ar u3
3-bit unsigned integer constant
.Po Sy 0
to
.Sy 7
.Pc .
.It Ar cc
Condition codes:
.Bl -tag -compact
.It Sy Z :
Execute if Z is set.
.It Sy NZ :
Execute if Z is not set.
.It Sy C :
Execute if C is set.
.It Sy NC :
Execute if C is not set.
.El
.It Ar vec
One of the
.Ar RST
vectors
.Po Sy 0x00 , 0x08 , 0x10 , 0x18 , 0x20 , 0x28 , 0x30
and
.Sy 0x38
.Pc .
.El
.Pp
.Sh INSTRUCTION OVERVIEW
.Ss 8-bit Arithmetic and Logic Instructions
.Bl -inset -compact
.It Sx ADC A,r8
.It Sx ADC A,[HL]
.It Sx ADC A,n8
.It Sx ADD A,r8
.It Sx ADD A,[HL]
.It Sx ADD A,n8
.It Sx AND A,r8
.It Sx AND A,[HL]
.It Sx AND A,n8
.It Sx CP A,r8
.It Sx CP A,[HL]
.It Sx CP A,n8
.It Sx DEC r8
.It Sx DEC [HL]
.It Sx INC r8
.It Sx INC [HL]
.It Sx OR A,r8
.It Sx OR A,[HL]
.It Sx OR A,n8
.It Sx SBC A,r8
.It Sx SBC A,[HL]
.It Sx SBC A,n8
.It Sx SUB A,r8
.It Sx SUB A,[HL]
.It Sx SUB A,n8
.It Sx XOR A,r8
.It Sx XOR A,[HL]
.It Sx XOR A,n8
.El
.Ss 16-bit Arithmetic Instructions
.Bl -inset -compact
.It Sx ADD HL,r16
.It Sx DEC r16
.It Sx INC r16
.El
.Ss Bit Operations Instructions
.Bl -inset -compact
.It Sx BIT u3,r8
.It Sx BIT u3,[HL]
.It Sx RES u3,r8
.It Sx RES u3,[HL]
.It Sx SET u3,r8
.It Sx SET u3,[HL]
.It Sx SWAP r8
.It Sx SWAP [HL]
.El
.Ss Bit Shift Instructions
.Bl -inset -compact
.It Sx RL r8
.It Sx RL [HL]
.It Sx RLA
.It Sx RLC r8
.It Sx RLC [HL]
.It Sx RLCA
.It Sx RR r8
.It Sx RR [HL]
.It Sx RRA
.It Sx RRC r8
.It Sx RRC [HL]
.It Sx RRCA
.It Sx SLA r8
.It Sx SLA [HL]
.It Sx SRA r8
.It Sx SRA [HL]
.It Sx SRL r8
.It Sx SRL [HL]
.El
.Ss Load Instructions
.Bl -inset -compact
.It Sx LD r8,r8
.It Sx LD r8,n8
.It Sx LD r16,n16
.It Sx LD [HL],r8
.It Sx LD [HL],n8
.It Sx LD r8,[HL]
.It Sx LD [r16],A
.It Sx LD [n16],A
.It Sx LD [$FF00+n8],A
.It Sx LD [$FF00+C],A
.It Sx LD A,[r16]
.It Sx LD A,[n16]
.It Sx LD A,[$FF00+n8]
.It Sx LD A,[$FF00+C]
.It Sx LD [HL+],A
.It Sx LD [HL-],A
.It Sx LD A,[HL+]
.It Sx LD A,[HL-]
.El
.Ss Jumps and Subroutines
.Bl -inset -compact
.It Sx CALL n16
.It Sx CALL cc,n16
.It Sx JP HL
.It Sx JP n16
.It Sx JP cc,n16
.It Sx JR e8
.It Sx JR cc,e8
.It Sx RET cc
.It Sx RET
.It Sx RETI
.It Sx RST vec
.El
.Ss Stack Operations Instructions
.Bl -inset -compact
.It Sx ADD HL,SP
.It Sx ADD SP,e8
.It Sx DEC SP
.It Sx INC SP
.It Sx LD SP,n16
.It Sx LD [n16],SP
.It Sx LD HL,SP+e8
.It Sx LD SP,HL
.It Sx POP AF
.It Sx POP r16
.It Sx PUSH AF
.It Sx PUSH r16
.El
.Ss Miscellaneous Instructions
.Bl -inset -compact
.It Sx CCF
.It Sx CPL
.It Sx DAA
.It Sx DI
.It Sx EI
.It Sx HALT
.It Sx NOP
.It Sx SCF
.It Sx STOP
.El
.Sh INSTRUCTION REFERENCE
.Ss ADC A,r8
Add the value in
.Ar r8
plus the carry flag to
.Sy A .
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
Set if overflow from bit 3.
.It
.Sy C :
Set if overflow from bit 7.
.El
.Ss ADC A,[HL]
Add the value pointed by
.Sy HL
plus the carry flag to
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: See
.Sx ADC A,r8
.Ss ADC A,n8
Add the value
.Ar n8
plus the carry flag to
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags: See
.Sx ADC A,r8
.Ss ADD A,r8
Add the value in
.Ar r8
to
.Sy A .
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
Set if overflow from bit 3.
.It
.Sy C :
Set if overflow from bit 7.
.El
.Ss ADD A,[HL]
Add the value pointed by
.Sy HL
to
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: See
.Sx ADD A,r8
.Ss ADD A,n8
Add the value
.Ar n8
to
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags: See
.Sx ADD A,r8
.Ss ADD HL,r16
Add the value in
.Ar r16
to
.Sy HL .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy N :
0
.It
.Sy H :
Set if overflow from bit 11.
.It
.Sy C :
Set if overflow from bit 15.
.El
.Ss ADD HL,SP
Add the value in
.Sy SP
to
.Sy HL .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: See
.Sx ADD HL,r16
.Ss ADD SP,e8
Add the signed value
.Ar e8
to
.Sy SP .
.Pp
Cycles: 4
.Pp
Bytes: 2
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
0
.It
.Sy N :
0
.It
.Sy H :
Set if overflow from bit 3.
.It
.Sy C :
Set if overflow from bit 7.
.El
.Ss AND A,r8
Bitwise AND between the value in
.Ar r8
and
.Sy A .
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
1
.It
.Sy C :
0
.El
.Ss AND A,[HL]
Bitwise AND between the value pointed by
.Sy HL
and
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: See
.Sx AND A,r8
.Ss AND A,n8
Bitwise AND between the value in
.Ar n8
and
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags: See
.Sx AND A,r8
.Ss BIT u3,r8
Test bit
.Ar u3
in register
.Ar r8 ,
set the zero flag if bit not set.
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if the selected bit is 0.
.It
.Sy N :
0
.It
.Sy H :
1
.El
.Ss BIT u3,[HL]
Test bit
.Ar u3
in the byte pointed by
.Sy HL ,
set the zero flag if bit not set.
.Pp
Cycles: 3
.Pp
Bytes: 2
.Pp
Flags: See
.Sx BIT u3,r8
.Ss CALL n16
Call address
.Ar n16 .
.Pp
Cycles: 6
.Pp
Bytes: 3
.Pp
Flags: None affected.
.Ss CALL cc,n16
Call address
.Ar n16
if condition
.Ar cc
is met.
.Pp
Cycles: 6/3
.Pp
Bytes: 3
.Pp
Flags: None affected.
.Ss CCF
Complement Carry Flag.
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Complemented.
.El
.Ss CP A,r8
Subtract the value in
.Ar r8
from
.Sy A
and set flags accordingly, but don't store the result.
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
1
.It
.Sy H :
Set if borrow from bit 4.
.It
.Sy C :
Set if borrow
.Po set if Ar r8
>
.Sy A
.Pc .
.El
.Ss CP A,[HL]
Subtract the value pointed by
.Sy HL
from
.Sy A
and set flags accordingly, but don't store the result.
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: See
.Sx CP A,r8
.Ss CP A,n8
Subtract the value
.Ar n8
from
.Sy A
and set flags accordingly, but don't store the result.
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags: See
.Sx CP A,r8
.Ss CPL
Complement accumulator
.Po Sy A
=
.Sy ~A
.Pc .
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy N :
1
.It
.Sy H :
1
.El
.Ss DAA
Decimal adjust register A to get a correct BCD representation after an
arithmetic instruction.
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy H :
0
.It
.Sy C :
Set or reset depending on the operation.
.El
.Ss DEC r8
Decrement value in register
.Ar r8
by 1.
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
1
.It
.Sy H :
Set if borrow from bit 4.
.El
.Ss DEC [HL]
Decrement the value pointed by
.Sy HL
by 1.
.Pp
Cycles: 3
.Pp
Bytes: 1
.Pp
Flags: See
.Sx DEC r8
.Ss DEC r16
Decrement value in register
.Ar r16
by 1.
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss DEC SP
Decrement value in register
.Sy SP
by 1.
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss DI
Disable Interrupts.
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss EI
Enable Interrupts.
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss HALT
Enter CPU low power mode.
.Pp
Cycles: -
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss INC r8
Increment value in register
.Ar r8
by 1.
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
Set if overflow from bit 3.
.El
.Ss INC [HL]
Increment the value pointed by
.Sy HL
by 1.
.Pp
Cycles: 3
.Pp
Bytes: 1
.Pp
Flags: See
.Sx INC r8
.Ss INC r16
Increment value in register
.Ar r16
by 1.
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss INC SP
Increment value in register
.Sy SP
by 1.
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss JP n16
Absolute jump to address
.Ar n16 .
.Pp
Cycles: 4
.Pp
Bytes: 3
.Pp
Flags: None affected.
.Ss JP cc,n16
Absolute jump to address
.Ar n16
if condition
.Ar cc
is met.
.Pp
Cycles: 4/3
.Pp
Bytes: 3
.Pp
Flags: None affected.
.Ss JP HL
Jump to address in
.Sy HL ,
that is, load
.Sy PC
with value in register
.Sy HL .
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss JR e8
Relative jump by adding
.Ar e8
to the current address.
.Pp
Cycles: 3
.Pp
Bytes: 2
.Pp
Flags: None affected.
.Ss JR cc,e8
Relative jump by adding
.Ar e8
to the current address if condition
.Ar cc
is met.
.Pp
Cycles: 3/2
.Pp
Bytes: 2
.Pp
Flags: None affected.
.Ss LD r8,r8
Store value in register on the right into register on the left.
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss LD r8,n8
Load value
.Ar n8
into register
.Ar r8 .
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags: None affected.
.Ss LD r16,n16
Load value
.Ar n16
into register
.Ar r16 .
.Pp
Cycles: 3
.Pp
Bytes: 3
.Pp
Flags: None affected.
.Ss LD [HL],r8
Store value in register
.Ar r8
into byte pointed by register
.Sy HL .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss LD [HL],n8
Store value
.Ar n8
into byte pointed by register
.Sy HL .
.Pp
Cycles: 3
.Pp
Bytes: 2
.Pp
Flags: None affected.
.Ss LD r8,[HL]
Load value into register
.Ar r8
from byte pointed by register
.Sy HL .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss LD [r16],A
Store value in register
.Sy A
into address pointed by register
.Ar r16 .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss LD [n16],A
Store value in register
.Sy A
into address
.Ar n16 .
.Pp
Cycles: 4
.Pp
Bytes: 3
.Pp
Flags: None affected.
.Ss LD [$FF00+n8],A
Store value in register
.Sy A
into high RAM or I/O registers.
.Pp
The following synonym forces this encoding:
.Sy LDH [$FF00+n8],A
.Pp
Cycles: 3
.Pp
Bytes: 2
.Pp
Flags: None affected.
.Ss LD [$FF00+C],A
Store value in register
.Sy A
into high RAM or I/O registers.
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss LD A,[r16]
Load value in register
.Sy A
from address pointed by register
.Ar r16 .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss LD A,[n16]
Load value in register
.Sy A
from address
.Ar n16 .
.Pp
Cycles: 4
.Pp
Bytes: 3
.Pp
Flags: None affected.
.Ss LD A,[$FF00+n8]
Load value in register
.Sy A
from high RAM or I/O registers.
.Pp
The following synonym forces this encoding:
.Sy LDH A,[$FF00+n8]
.Pp
Cycles: 3
.Pp
Bytes: 2
.Pp
Flags: None affected.
.Ss LD A,[$FF00+C]
Load value in register
.Sy A
from high RAM or I/O registers.
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss LD [HL+],A
Store value in register
.Sy A
into byte pointed by
.Sy HL
and post-increment
.Sy HL .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss LD [HL-],A
Store value in register
.Sy A
into byte pointed by
.Sy HL
and post-decrement
.Sy HL .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss LD A,[HL+]
Load value into register
.Sy A
from byte pointed by
.Sy HL
and post-increment
.Sy HL .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss LD A,[HL-]
Load value into register
.Sy A
from byte pointed by
.Sy HL
and post-decrement
.Sy HL .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss LD SP,n16
Load value
.Ar n16
into register
.Sy SP .
.Pp
Cycles: 3
.Pp
Bytes: 3
.Pp
Flags: None affected.
.Ss LD [n16],SP
Store
.Sy SP
into addresses
.Ar n16
(LSB) and
.Ar n16
+ 1 (MSB).
.Pp
Cycles: 5
.Pp
Bytes: 3
.Pp
Flags: None affected.
.Ss LD HL,SP+e8
Add the signed value
.Ar e8
to
.Sy SP
and store the result in
.Sy HL.
.Pp
Cycles: 3
.Pp
Bytes: 2
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
0
.It
.Sy N :
0
.It
.Sy H :
Set if overflow from bit 3.
.It
.Sy C :
Set if overflow from bit 7.
.El
.Ss LD SP,HL
Load register
.Sy HL
into register
.Sy SP .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss NOP
No operation.
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss OR A,r8
Bitwise OR between the value in
.Ar r8
and
.Sy A .
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
0
.El
.Ss OR A,[HL]
Bitwise OR between the value pointed by
.Sy HL
and
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: See
.Sx OR A,r8
.Ss OR A,n8
Bitwise OR between the value in
.Ar n8
and
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags: See
.Sx OR A,r8
.Ss POP AF
Pop register
.Sy AF
from the stack.
.Pp
Cycles: 3
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set from bit 7 of the popped low byte.
.It
.Sy N :
Set from bit 6 of the popped low byte.
.It
.Sy H :
Set from bit 5 of the popped low byte.
.It
.Sy C :
Set from bit 4 of the popped low byte.
.El
.Ss POP r16
Pop register
.Ar r16
from the stack.
.Pp
Cycles: 3
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss PUSH AF
Push register
.Sy AF
into the stack. The low byte's bit 7 corresponds to the
.Sy Z
flag, its bit 6 to the
.Sy N
flag, bit 5 to the
.Sy H
flag, and bit 4 to the
.Sy C
flag. Bits 3 to 0 are reset.
.Pp
Cycles: 4
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss PUSH r16
Push register
.Ar r16
into the stack.
.Pp
Cycles: 4
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss RES u3,r8
Set bit
.Ar u3
in register
.Ar r8
to 0.
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags: None affected.
.Ss RES u3,[HL]
Set bit
.Ar u3
in the byte pointed by
.Sy HL
to 0.
.Pp
Cycles: 4
.Pp
Bytes: 2
.Pp
Flags: None affected.
.Ss RET
Return from subroutine.
.Pp
Cycles: 4
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss RET cc
Return from subroutine if condition
.Ar cc
is met.
.Pp
Cycles: 5/2
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss RETI
Return from subroutine and enable interrupts.
.Pp
Cycles: 4
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss RL r8
Rotate register
.Ar r8
left through carry.
.Pp
.D1 C <- [7 <- 0] <- C
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Set according to result.
.El
.Ss RL [HL]
Rotate value pointed by
.Sy HL
left through carry.
.Pp
.D1 C <- [7 <- 0] <- C
.Pp
Cycles: 4
.Pp
Bytes: 2
.Pp
Flags: See
.Sx RL r8
.Ss RLA
Rotate register
.Sy A
left through carry.
.Pp
.D1 C <- [7 <- 0] <- C
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
0
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Set according to result.
.El
.Ss RLC r8
Rotate register
.Ar r8
left.
.Pp
.D1 C <- [7 <- 0] <- [7]
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Set according to result.
.El
.Ss RLC [HL]
Rotate value pointed by
.Sy HL
left.
.Pp
.D1 C <- [7 <- 0] <- [7]
.Pp
Cycles: 4
.Pp
Bytes: 2
.Pp
Flags: See
.Sx RLC r8
.Ss RLCA
Rotate register
.Sy A
left.
.Pp
.D1 C <- [7 <- 0] <- [7]
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
0
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Set according to result.
.El
.Ss RR r8
Rotate register
.Ar r8
right through carry.
.Pp
.D1 C -> [7 -> 0] -> C
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Set according to result.
.El
.Ss RR [HL]
Rotate value pointed by
.Sy HL
right through carry.
.Pp
.D1 C -> [7 -> 0] -> C
.Pp
Cycles: 4
.Pp
Bytes: 2
.Pp
Flags: See
.Sx RR r8
.Ss RRA
Rotate register
.Sy A
right through carry.
.Pp
.D1 C -> [7 -> 0] -> C
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
0
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Set according to result.
.El
.Ss RRC r8
Rotate register
.Ar r8
right.
.Pp
.D1 [0] -> [7 -> 0] -> C
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Set according to result.
.El
.Ss RRC [HL]
Rotate value pointed by
.Sy HL
right.
.Pp
.D1 [0] -> [7 -> 0] -> C
.Pp
Cycles: 4
.Pp
Bytes: 2
.Pp
Flags: See
.Sx RRC r8
.Ss RRCA
Rotate register
.Sy A
right.
.Pp
.D1 [0] -> [7 -> 0] -> C
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
0
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Set according to result.
.El
.Ss RST vec
Call restart vector
.Ar vec .
.Pp
Cycles: 4
.Pp
Bytes: 1
.Pp
Flags: None affected.
.Ss SBC A,r8
Subtract the value in
.Ar r8
and the carry flag from
.Sy A .
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
1
.It
.Sy H :
Set if borrow from bit 4.
.It
.Sy C :
Set if borrow
.Po set if Ar r8
>
.Sy A
.Pc .
.El
.Ss SBC A,[HL]
Subtract the value pointed by
.Sy HL
and the carry flag from
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: See
.Sx SBC A,r8
.Ss SBC A,n8
Subtract the value
.Ar n8
and the carry flag from
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags: See
.Sx SBC A,r8
.Ss SCF
Set Carry Flag.
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
1
.El
.Ss SET u3,r8
Set bit
.Ar u3
in register
.Ar r8
to 1.
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags: None affected.
.Ss SET u3,[HL]
Set bit
.Ar u3
in the byte pointed by
.Sy HL
to 1.
.Pp
Cycles: 4
.Pp
Bytes: 2
.Pp
Flags: None affected.
.Ss SLA r8
Shift left arithmetic register
.Ar r8 .
.Pp
.D1 C <- [7 <- 0] <- 0
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Set according to result.
.El
.Ss SLA [HL]
Shift left arithmetic value pointed by
.Sy HL .
.Pp
.D1 C <- [7 <- 0] <- 0
.Pp
Cycles: 4
.Pp
Bytes: 2
.Pp
Flags: See
.Sx SLA r8
.Ss SRA r8
Shift right arithmetic register
.Ar r8 .
.Pp
.D1 [7] -> [7 -> 0] -> C
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Set according to result.
.El
.Ss SRA [HL]
Shift right arithmetic value pointed by
.Sy HL .
.Pp
.D1 [7] -> [7 -> 0] -> C
.Pp
Cycles: 4
.Pp
Bytes: 2
.Pp
Flags: See
.Sx SRA r8
.Ss SRL r8
Shift right logic register
.Ar r8 .
.Pp
.D1 0 -> [7 -> 0] -> C
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
Set according to result.
.El
.Ss SRL [HL]
Shift right logic value pointed by
.Sy HL .
.Pp
.D1 0 -> [7 -> 0] -> C
.Pp
Cycles: 4
.Pp
Bytes: 2
.Pp
Flags: See
.Sx SRA r8
.Ss STOP
Enter CPU very low power mode.
Also used to switch between double and normal speed CPU modes in GBC.
.Pp
Cycles: -
.Pp
Bytes: 2
.Pp
Flags: None affected.
.Ss SUB A,r8
Subtract the value in
.Ar r8
from
.Sy A .
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
1
.It
.Sy H :
Set if borrow from bit 4.
.It
.Sy C :
Set if borrow
.Po set if Ar r8
>
.Sy A
.Pc .
.El
.Ss SUB A,[HL]
Subtract the value pointed by
.Sy HL
from
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: See
.Sx SUB A,r8
.Ss SUB A,n8
Subtract the value
.Ar n8
from
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags: See
.Sx SUB A,r8
.Ss SWAP r8
Swap upper 4 bits in register
.Ar r8
and the lower ones.
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
0
.El
.Ss SWAP [HL]
Swap upper 4 bits in the byte pointed by
.Sy HL
and the lower ones.
.Pp
Cycles: 4
.Pp
Bytes: 2
.Pp
Flags: See
.Sx SWAP r8
.Ss XOR A,r8
Bitwise XOR between the value in
.Ar r8
and
.Sy A .
.Pp
Cycles: 1
.Pp
Bytes: 1
.Pp
Flags:
.Bl -bullet -compact
.It
.Sy Z :
Set if result is 0.
.It
.Sy N :
0
.It
.Sy H :
0
.It
.Sy C :
0
.El
.Ss XOR A,[HL]
Bitwise XOR between the value pointed by
.Sy HL
and
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 1
.Pp
Flags: See
.Sx XOR A,r8
.Ss XOR A,n8
Bitwise XOR between the value in
.Ar n8
and
.Sy A .
.Pp
Cycles: 2
.Pp
Bytes: 2
.Pp
Flags: See
.Sx XOR A,r8
.Sh SEE ALSO
.Xr rgbasm 1 ,
.Xr rgbds 7
.Sh HISTORY
.Nm rgbds
was originally written by Carsten S\(/orensen as part of the ASMotor package,
and was later packaged in RGBDS by Justin Lloyd.
It is now maintained by a number of contributors at
.Lk https://github.com/rednex/rgbds .