Intel mcs-48 IputoPort 0 Data to Accumulator 8021, 8022 Only, JC address Jump If Carry Is Set

INSTRUCTION SET

IN A,PO I"puto'Port 0 Data to Accumulator (8021, 8022 Only)

Same as INS A,BUS except no RD pulse generated.

INS A,BUS Strobed I"put of BUS Data to Accumulator

10000110001

This is a 2-cycle instruction. Data present on the BUS port is transferred (read) to the accumulator when the RD pulse is dropped. (Refer to section on programming memory expansion for details).

(A) __ (BUS)

Example: INPBUS: INS A,BUS ;INPUT BUS CONTENTS ;TO ACC

JBb address Jump If Accumulator Bit is Set (Not in 8021, 8022)

Ib2 b1 bo 1 I0 0 1 0 I 1a7 a6 as a4 Ia3 a2 a1 aO I

This is a 2-cycle instruction. Control passes to the specified address if accumulator bit 'b'is set

to one.	b=0-7
(PCO-7)-- addr	If Bb=1
(PC) = (PC)+2	If Bb=O
Example: JB4IS1: JB4 NEXT	;JUMP TO 'NEXT'ROUTINE
	;IF ACC BIT 4=1

JC address Jump If Carry Is Set

11 1 1 1 10 1 1 0 1 Ia7 a6 as a4 Ia3 a2 a1 aO I

This is a 2-cycle instruction. Control passes to the specified address if the carry bit is set to one.

(PCO-7)-- addr	If C=1
(PC) = (PC)+2	If C=O
Example: JC1: JC OVFLOW	;JUMP TO 'OVFLOW'ROUTINE
	;IF C=1

JFO address Jump If Flag Ols Set (Not in 8021, 8022)

11 0 1 1 10 1 1 0 1 ~ a6 as a4 Ia3 a2 a1 ao I

This is a 2-cycle instruction. Control passes to the specified address if flag 0 is set to one.

(PCO-7)-- addr	If FO=1
(PC) = (PC)+2	If FO=O
Example: JFOIS1: JFO TOTAL	;JUMP TO 'TOTAL'ROUTINE
	;IF FO=1

Mnemonics copyright Intel Corporation 1976.

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