Intel 80C196NU, 8XC196NP, Microcontroller manual Subb, Subc Subtract Words with Borrow DEST, SRC

INSTRUCTION SET REFERENCE

Table A-6. Instruction Set (Continued)

Mnemonic				Operation						Instruction Format
SUBB	SUBTRACT BYTES. Subtracts the source									DEST, SRC
(2 operands)	byte operand from the destination byte								SUBB	breg, baop
	operand, stores the result in the destination
									(011110aa) (baop) (breg)
	operand, and sets the carry flag as the
	complement of borrow.
	(DEST) ← (DEST) – (SRC)
			PSW Flag Settings
		Z	N	C	V		VT	ST
		✓	✓	✓	✓		−	—
SUBB	SUBTRACT BYTES. Subtracts the first									DEST, SRC1, SRC2
(3 operands)	source byte operand from the second, stores								SUBB	Dbreg, Sbreg, baop
	the result in the destination operand, and sets
									(010110aa) (baop) (Sbreg) (Dbreg)
	the carry flag as the complement of borrow.
	(DEST) ← (SRC1) – (SRC2)
			PSW Flag Settings
		Z	N	C	V		VT	ST
		✓	✓	✓	✓		−	—
SUBC	SUBTRACT WORDS WITH BORROW.									DEST, SRC
	Subtracts the source word operand from the								SUBC	wreg, waop
	destination word operand. If the carry flag
									(101010aa) (waop) (wreg)
	was clear, SUBC subtracts 1 from the result.
	It stores the result in the destination operand
	and sets the carry flag as the complement of
	borrow.
	(DEST) ← (DEST) – (SRC) – (1–C)
			PSW Flag Settings
		Z	N	C	V		VT	ST
		↓	✓	✓	✓	−		—
SUBCB	SUBTRACT BYTES WITH BORROW.									DEST, SRC
	Subtracts the source byte operand from the								SUBCB	breg, baop
	destination byte operand. If the carry flag was
									(101110aa) (baop) (breg)
	clear, SUBCB subtracts 1 from the result. It
	stores the result in the destination operand
	and sets the carry flag as the complement of
	borrow.
	(DEST) ← (DEST) – (SRC) – (1–C)
			PSW Flag Settings
		Z	N	C	V		VT	ST
		↓	✓	✓	✓		−	—

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