Intel 80287 Jae, Jbe, Jge, Jle, Jnb, Jnc, Zf=O, Jne, Jng, Sf=Of, Jno, Jnp, Jns, Jnz, Jpe, Jpo

THE 80286 INSTRUCTION SET

Jcond-JumpShort If Condition Met

Opcode		Instruction			Clocks·	Description
77	cb	JA cb			7,noj=3	Jump short if above (CF=O and ZF=O)
73	cb	JAE		cb	7,noj=3	Jump short if above or equal (CF=O)
72	cb	JB	cb		7,noj=3	Jump short if below (CF=1)
76	cb	JBE		cb	7,noj=3	Jump short if below or equal (CF=1 or ZF=1)
72	cb	JC	cb		7,noj=3	Jump short if carry (CF=1)
E3	cb	JCXZ cb			8,noj=4	Jump short if CX register is zero
74	cb	JE cb			7,noj=3	Jump short if equal (ZF=1)
7F	cb	JG	cb		7,noj=3	Jump short if greater (ZF=O and SF=OF)
70	cb	JGE		cb	7,noj=3	Jump short if greater or equal (SF=OF)
7C	cb	JL cb			7,noj=3	Jump short if less (SF/=OF)
7E	cb	JLE		cb	7,noj=3	Jump short if less or equal (ZF=1 or SF/=OF)
76	cb	JNA cb			7,noj=3	Jump short if not above (CF=1 or ZF=1)
72	cb	JNAE cb			7,noj=3	Jump short if not above/equal (CF=1)
73	cb	JNB		cb	7,noj=3	Jump short if not below (CF=O)
77	cb	JNBE cb			7,noj=3	Jump short if not below/equal (CF=O and
73	cb	JNC		cb	7,noj=3	ZF=O)
						Jump short if not carry (CF=O)
75	cb	JNE		cb	7,noj=3	Jump short if not equal (ZF=O)
7E	cb	JNG		cb	7,noj=3	Jump short if not greater (ZF=1 or SF/=OF)
7C	cb	JNGE cb			7,noj=3	Jump short if not greater/equal (SF/=OF)
70	cb	JNL cb			7,noj=3	Jump short if not less (SF=OF)
7F	cb	JNLE cb			7,noj=3	Jump short if not less/equal (ZF=O and
71	cb			cb	7,noj=3	SF=OF)
		JNO				Jump short if not overflow (OF=O)
7B	cb	JNP		cb	7,noj=3	Jump short if not parity (PF=O)
79	cb	JNS		cb	7,noj=3	Jump short if not sign (SF=O)
75	cb	JNZ		cb	7,noj=3	Jump short if not zero (ZF=O)
70	cb	JO	cb		7,noj=3	Jump short if overflow (OF=1)
7A	cb	JP	cb		7,noj=3	Jump short if parity (PF=1)
7A	cb	JPE		cb	7,noj=3	Jump short if parity even (PF=1)
7B	cb	JPO		cb	7,noj=3	Jump short if parity odd (PF=O)
78	cb	JS	cb		7,noj=3	Jump short if sign (SF=1)
74	cb	JZ	cb		7,noj=3	Jump short if zero (ZF=1)

'Whena jump is taken, add one clock fo; eVery byte of the next instruction executed.

FLAGS MODIFIED

None

FLAGS UNDEFINED

None

OPERATION

Conditional jumps (except for JCXZ, explained below) test the flags, which presumably have been set in some meaningful way by a previous instruction. The conditions for each mnemonic are given in parentheses after each description above. The terms "less" and "greater" are used for comparing signed integers; "above" and "below" are used for unsigned integers.

B-54