Chapter 6 peripheral hardware function, 1 digital i/o ports – NEC PD754144 User Manual

Page 88

User’s Manual U10676EJ3V0UM

CHAPTER 6 PERIPHERAL HARDWARE FUNCTION

6.1 Digital I/O Ports

The

µPD754244 uses memory mapped I/O, and all the I/O ports are mapped to the data memory space.

Figure 6-1. Data Memory Address of Digital Ports

FF0H

FF1H

FF2H

FF3H

FF4H

FF5H

FF6H

FF7H

FF8H

P33

P63

P73

–

Address

P32

P62

P72

–

P31

P61

P71

–

P30

P60

P70

P80

Port 3

Port 6

Port 7

Port 8

—

Table 6-2 lists the instructions that manipulate the I/O ports. Ports 3 and 6 can be manipulated in 4-I/O and

1-bit units. They are used for various control operations.

Examples 1. To test the status of P73 and outputs different values to port 3 depending on the result

SKT

PORT7.3

; Skips if bit 3 of port 7 is 1

MOV

XA, #8H

; XA

← 8H

MOV

XA, #4H

; XA

← 4H

SEL

MB15

; or CLR1 MBE

OUT

PORT3, A

; Port 3

← A

2. SET1

PORT6.@L ; Sets the bits of port 6 specified by the L register to “1”

String effect

This manual is related to the following products:

PD754244