SCHG:68000 Instruction Set
From Sonic Retro
| Instruction | Description | Assembler Syntax | Data Size | Condition Codes X N Z V C |
|---|---|---|---|---|
| ABCD | Add BCD with Extend | Dx,Dy -(Ax),-(Ay) | B-- | * U * U * |
| ADD | ADD binary | Dn,< ea > < ea >,Dn | BWL | * * * * * |
| ADDA | ADD binary to An | < ea >,An | -WL | - - - - - |
| ADDI | Add Immediate | #x,< ea > | BWL | * * * * * |
| ADDQ | ADD 3-bit immediate | #<1-8>,< ea > | BWL | * * * * * |
| ADDX | ADD eXtended | Dy,Dx -(Ay),-(Ax) | BWL | * * * * * |
| AND | Bit-wise AND | < ea >,Dn Dn,< ea > | BWL | - * * 0 0 |
| ANDI | Bit-wise AND with Immediate | #< data>,< ea > | BWL | - * * 0 0 |
| ASL | Arithmetic Shift Left | #<1-8>,Dy Dx,Dy < ea > | BWL | * * * * * |
| ASR | Arithmetic Shift Right | ... | BWL | * * * * * |
| Bcc | Conditional Branch | Bcc.S < label> Bcc.W < label> | BW- | - - - - - |
| BCHG | Test a Bit and ChanGe | Dn,< ea > #< data>,< ea > | B-L | - - * - - |
| BCLR | Test a Bit and CLEAR | ... | B-L | - - * - - |
| BSET | Test a Bit and SET | ... | B-L | - - * - - |
| BSR | Branch to SubRoutine | BSR.S < label> BSR.W < label> | BW- | - - - - - |
| BTST | Bit TeST | Dn,< ea > #< data>,< ea > | B-L | - - * - - |
| CHK | CHecK Dn Against Bounds | < ea >,Dn | -W- | - * U U U |
| CLR | CLEAR | < ea > | BWL | - 0 1 0 0 |
| CMP | CoMPare | < ea >,Dn | BWL | - * * * * |
| CMPA | CoMPare Address | < ea >,An | -WL | - * * * * |
| CMPI | CoMPare Immediate | #< data>,< ea > | BWL | - * * * * |
| CMPM | CoMPare Memory | (Ay)+,(Ax)+ | BWL | - * * * * |
| DBcc | Looping Instruction | DBcc Dn,< label> | -W- | - - - - - |
| DIVS | DIVide Signed | < ea >,Dn | -W- | - * * * 0 |
| DIVU | DIVide Unsigned | < ea >,Dn | -W- | - * * * 0 |
| EOR | Exclusive OR | Dn,< ea > | BWL | - * * 0 0 |
| EORI | Exclusive OR Immediate | #< data>,< ea > | BWL | - * * 0 0 |
| EXG | Exchange any two registers | Rx,Ry | --L | - - - - - |
| EXT | Sign EXTend | Dn | -WL | - * * 0 0 |
| ILLEGAL | ILLEGAl-Instruction Exception | ILLEGAL | - - - - - | |
| JMP | JuMP to Affective Address | < ea > | - - - - - | |
| JSR | Jump to SubRoutine | < ea > | - - - - - | |
| LEA | Load Effective Address | < ea >,An | --L | - - - - - |
| LINK | Allocate Stack Frame | An,#< displacement> | - - - - - | |
| LSL | Logical Shift Left | Dx,Dy #<1-8>,Dy < ea > | BWL | * * * 0 * |
| LSR | Logical Shift Right | ... | BWL | * * * 0 * |
| MOVE | Between Effective Addresses | < ea >,< ea > | BWL | - * * 0 0 |
| MOVE | To CCR | < ea>,CCR | -W- | I I I I I |
| MOVE | To SR | < ea >,SR | -W- | I I I I I |
| MOVE | From SR | SR,< ea > | -W- | - - - - - |
| MOVE | USP to/from Address Register | USP,An An,USP | --L | - - - - - |
| MOVEA | MOVE Address | < ea >,An | -WL | - - - - - |
| MOVEM | MOVE Multiple | <register list>,< ea > < ea >,<register list> | -WL | - - - - - |
| MOVEP | Move Peripheral | Dn,x(An) x(An),Dn | -WL | - - - - - |
| MOVEQ | Move 8-bit immediate | #<-128.+127>,Dn | --L | - * * 0 0 |
| MULS | MULtiply Signed | < ea >,Dn | -W- | - * * 0 0 |
| MULU | MULtiply Unsigned | < ea >,Dn | -W- | - * * 0 0 |
| NBCD | Negate BCD | < ea > | B-- | * U * U * |
| NEG | NEGate | < ea > | BWL | * * * * * |
| NEGX | NEGate with eXtend | < ea > | BWL | * * * * * |
| NOP | No OPeration | NOP | - - - - - | |
| NOT | Form one's complement | < ea > | BWL | - * * 0 0 |
| OR | Bit-wise OR | < ea >,Dn Dn,< ea > | BWL | - * * 0 0 |
| ORI | Bit-wise OR with Immediate | #< data>,< ea > | BWL | - * * 0 0 |
| PEA | Push Effective Address | < ea > | --L | - - - - - |
| RESET | RESET all external devices | RESET | - - - - - | |
| ROL | ROtate Left | #<1-8>,Dy Dx,Dy < ea > | BWL | - * * 0 * |
| ROR | ROtate Right | ... | BWL | - * * 0 * |
| ROXL | ROtate Left with eXtend | ... | BWL | * * * 0 * |
| ROXR | ROtate Right with eXtend | ... | BWL | * * * 0 * |
| RTE | ReTurn from Exception | RTE | I I I I I | |
| RTR | ReTurn and Restore | RTR | I I I I I | |
| RTS | ReTurn from Subroutine | RTS | - - - - - | |
| SBCD | Subtract BCD with eXtend | Dx,Dy -(Ax),-(Ay) | B-- | * U * U * |
| Scc | Set to -1 if True, 0 if False | < ea > | B-- | - - - - - |
| STOP | Enable & wait for interrupts | #< data> | I I I I I | |
| SUB | SUBtract binary | Dn,< ea > < ea >,Dn | BWL | * * * * * |
| SUBA | SUBtract binary from An | < ea >,An | -WL | - - - - - |
| SUBI | SUBtract Immediate | #x,< ea > | BWL | * * * * * |
| SUBQ | SUBtract 3-bit immediate | #< data>,< ea > | BWL | * * * * * |
| SUBX | SUBtract eXtended | Dy,Dx -(Ay),-(Ax) | BWL | * * * * * |
| SWAP | SWAP words of Dn | Dn | -W- | - * * 0 0 |
| TAS | Test & Set MSB & Set N/Z-bits | < ea > | B-- | - * * 0 0 |
| TRAP | Execute TRAP Exception | #< vector> | - - - - - | |
| TRAPV | TRAPV Exception if V-bit Set | TRAPV | - - - - - | |
| TST | TeST for negative or zero | < ea > | BWL | - * * 0 0 |
| UNLK | Deallocate Stack Frame | An | - - - - - |
Legend
- * - Set according to result of operation
- - - Not affected
- 0 - Cleared
- 1 - Set
- U - Outcome (state after operation) undefined
- I - Set by immediate data
- < ea > - Effective Address Operand
- < data> - Immediate data
- < label> - Assembler label
- < vector> TRAP instruction Exception vector (0-15)
- < rg.lst> MOVEM instruction register specification list
- < displ.> LINK instruction negative displacement
- ... - Same as previous isntruction
| Addressing Modes | Syntax |
|---|---|
| Data Register Direct | Dn |
| Address Register Direct | An |
| Address Register Indirect | (An) |
| Address Register Indirect with Post-Increment | (An)+ |
| Address Register Indirect with Pre-Decrement | -(An) |
| Address Register Indirect with Displacement | w(An) |
| Address Register Indirect with Index | b(An,Rx) |
| Absolute Short | w |
| Absolute Long | l |
| Program Counter with Displacement | w(PC) |
| Program Counter with Index | b(PC,Rx) |
| Immediate | #x |
| Status Register | SR |
| Condition Code Register | CCR |
Legend
- Dn - Data Register (n is 0-7)
- An - Address Register (n is 0-7)
- b - 08-bit constant
- w - 16-bit constant
- l - 32-bit constant
- x - 8-, 16-, 32-bit constant
- Rx - Index Register Specification, one of:
- Dn.W - Low 16 bits of Data Register
- Dn.L - All 32 bits of Data Register
- An.W - Low 16 bits of Address Register
- An.L - All 32 bits of Address Register
Condition Codes for Bcc, DBcc and Scc Instructions
Condition Codes set after CMP D0,D1 Instruction.
| Relationship | Unsigned | Signed |
|---|---|---|
| D1 < D0 | CS - Carry Bit Set | LT - Less Than |
| D1 <= D0 | LS - Lower or Same | LE - Less than or Equal |
| D1 = D0 | EQ - Equal (Z-bit Set) | |
| D1 != D0 | NE - Not Equal (Z-bit Clear) | |
| D1 > D0 | HI - HIgher than | GT - Greater Than |
| D1 >= D0 | CC - Carry Bit Clear | GE - Greater than or Equal |
| PL - PLus (N-bit Clear) | ||
| MI - Minus (N-bit Set) | ||
| VC - V-bit Clear (No Overflow) | ||
| VS - V-bit Set (Overflow) | ||
| Bcc only | ||
| RA - BRanch Always | ||
| DBcc only | ||
| F - Never Terminate (DBRA is an alternate to DBF) | ||
| T - Always Terminate | ||
| Scc only | ||
| SF - Never Set | ||
| ST - Always Set | ||
