Integer Instructions
MOTOROLA M68000 FAMILY PROGRAMMER’S REFERENCE MANUAL 4-177
SUBA Subtract Address SUBA
(M68000 Family)
Operation: Destination – Source → Destination
Assembler
Syntax: SUBA < ea > ,An
Attributes: Size = (Word, Long)
Description: Subtracts the source operand from the destination address register and stores
the result in the address register. The size of the operation is specified as word or long.
Word-sized source operands are sign-extended to 32-bit quantities prior to the
subtraction.
Condition Codes:
Not affected.
Instruction Format:
Instruction Fields:
Register field—Specifies the destination, any of the eight address registers.
Opmode field—Specifies the size of the operation.
011—Word operation. The source operand is sign-extended to a long operand and
the operation is performed on the address register using all 32 bits.
111— Long operation.
1514131211109876543210
1001 REGISTER OPMODE
EFFECTIVE ADDRESS
MODE REGISTER
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