Address Movement

 Address movement instructions move addresses from one location to another. The source and destination locations are determined by the addressing modes, and can be registers or memory. Address movement instructions can come in a variety of sizes. Address movement instructions destroy the previous contents of the destination. Address movement instructions typically do not modify processor flags. When the destination is a register and the address is smaller than the full register size, the data might be placed only in the low order bits (leaving high order bits unchanged), or might be zero- or sign-extended to fill the entire register (some processors only use one choice, others permit the programmer to choose how this is handled).

• MOVEA.W Move Address (Word); Motorola 680x0, Motorola 68300; move an address word (16 bits) as sign-extended data (32 bits); memory to address register or register to address register; does not modify flags
• MOVEA.L Move Address (Longword); Motorola 680x0, Motorola 68300; move an address longword (32 bits); memory to address register or register to address register; does not modify flags
• LEA Load Effective Address; Motorola 680x0, Motorola 68300; computes an effective address and loads the result into an address register
• LA Load Address; RX format; IBM 360/370; computes an effective address and loads the 24-bit result (zero extended to 32-bits) into a general purpose register; does not affect condition code
• ENTA Enter A-register; MIX; move word or partial word field contents of index register to A-register (accumulator)
• ENTX Enter X-register; MIX; move word or partial word field contents of index register to X-register (extension)
• ENTi Enter I-register; MIX; move word or partial word field contents of index register to designated index register
• ENNA Enter Negative A-register; MIX; move word or partial word field contents of index register to A-register (accumulator), opposite sign loaded
• ENNX Enter Negative X-register; MIX; move word or partial word field contents of index register to X-register (extension), opposite sign loaded
• ENNi Enter Negative I-register; MIX; move word or partial word field contents of index register to designated index register, opposite sign loaded
• INCA Increase A-register; MIX; add word or partial word field contents of memory to A-register (accumulator), overflow toggle possibly set
• INCX Increase X-register; MIX; add word or partial word field contents of memory to X-register (extension), overflow toggle possibly set
• INCi Increase I-register; MIX; add word or partial word field contents of memory to designated index register, overflow toggle possibly set
• DECA Decrease A-register; MIX; subtract word or partial word field contents of memory from A-register (accumulator), overflow toggle possibly set
• DECX Decrease X-register; MIX; subtract word or partial word field contents of memory from X-register (extension), overflow toggle possibly set
• DECi Decrease I-register; MIX; subtract word or partial word field contents of memory from designated index register, overflow toggle possibly set
• PEA Push Effective Address; Motorola 680000; computes an effective address and pushes the result onto a stack (predecrementing an address register acting as a stack pointer)
• LINK Link Stack; Motorola 680000
• UNLK Unlink Stack; Motorola 680000