Chapter 5 Peripheral Hardware Functions; Digital I/O Ports; Data Memory Addresses Of Digital Ports - NEC PD750004 User Manual

CHAPTER 5 PERIPHERAL HARDWARE FUNCTIONS

5.1

DIGITAL I/O PORTS

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.
Example 1. To test the condition of P13 and output different values to ports 4 and 5 according to the test
result:
SKT
MOV
MOV
SEL
OUT
2. SET1 PORT4. @L; Sets the bit(s) specified by the L register, in ports 4 to 7, to 1.
Figure 5-1. Data Memory Addresses of Digital Ports
Address
3
FF0H P03 P02
FF1H P13 P12
FF2H P23 P22
FF3H P33 P32
FF4H P43 P42
FF5H P53 P52
FF6H P63 P62
P73 P72
FF7H
FF8H –
PORT1. 3 ; Skips if bit 3 of port 1 is 1
XA, #18H ; XA <– 18H
XA, #14H ; XA <– 14H
MB15 ; Or CLR1 MBE
PORT4, XA ; Port 5, 4 <– XA
CHAPTER 5 PERIPHERAL HARDWARE FUNCTIONS
2 1 0
P01 P00 PORT 0
P11 P10 PORT 1
P21 P20 PORT 2
P31 P30 PORT 3
P41 P40 PORT 4
P51 P50 PORT 5
P61 P60 PORT 6
P71 P70 PORT 7
– P81 P80 PORT 8
String-effect instructions
5
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