NEC PD754244 Manuel D’Utilisation

User’s Manual  U10676EJ3V0UM

The 

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

FF0H

FF1H

FF2H

FF3H

FF4H

FF5H

FF6H

FF7H

FF8H

P33

P63

P73

–

Address

3

P32

P62

P72

–

2

P31

P61

P71

–

1

P30

P60

P70

P80

0

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