MPD78C14 datasheet(91/373 Pages) NEC

91 / 373 page

CHAPTER 4

PORT FUNCTIONS

4.6 Operation of Arithmetic and Logical Operation Instruction Involving a Port and Immediate Data

With the following instructions which perform arithmetic and logical operations involving a port and immediate

data, the operation differs depending on the input/output setting of the port.

Table 4-4. Operation of Arithmetic/Logical Operation Instructions Involving a Port

Mnemonic

Operand

Instruction

ACI, ADI, ADINC

sr2, byte

Arithmetic operation

SBI, SUI, SUINB

ANI, ORI, XRI

Logical operation

GTI, LTI

Comparison

EQI, NEI

Match detection

OFFI, ONI

Test

Instruction operations are as follows:

(1) The port status is input.

Output mode pin:

Output latch status is input.

Input mode pin:

Pin external status is input.

(2) The arithmetic/logical operation is performed on the input data and immediate data.

(3) The entire 8-bit operation result data is transferred to the port output latch.

For input mode pins, the result of the operation with the pin external status is transferred to the output latch.

Caution (3) applies only to the arithmetic operations and logical operations in Table 4-4.

Port output latch initialization should be performed by a transfer instruction (MOV, MVI).

MPD78C14 Datasheet(PDF) 91 Page - NEC