NEC PD750008 Manuale Utente

The µPD750008 employs the memory mapped I/O method.  Thus, all input/output ports are mapped on

the data memory space.

Remark Some I/O parts can be used as static RAM.

Input/output port manipulation instructions are as listed in Table 5-2.  Ports 4 to 7 can be manipulated not

only in 4-bit units, but also in 8-bit or 1-bit units so that these ports can be controlled in various ways.

To test the condition of P13 and output different values to ports 4 and 5 according to the test

result:

SKT

PORT1. 3

; Skips if bit 3 of port 1 is 1

MOV

XA, #18H

; XA <– 18H

String-effect instructions

MOV

XA, #14H

; XA <– 14H

SEL

MB15

; Or CLR1 MBE

OUT

PORT4, XA ; Port 5, 4 <– XA

2. SET1

PORT4. @L; Sets the bit(s) specified by the L register, in ports 4 to 7, to 1.

P03

P02

P01

P00

P13

P12

P11

P10

P23

P22

P21

P20

P33

P32

P31

P30

P43

P42

P41

P40

P53

P52

P51

P50

P63

P62

P61

P60

–

–

P81

P80

PORT 0

PORT 1

PORT 2

PORT 3

PORT 4

PORT 5

PORT 6

PORT 8

FF0H

FF1H

FF2H

FF3H

FF4H

FF5H

FF6H

FF8H

Address

3

2

1

0

FF7H

P73

P72

P71

P70

PORT 7