User’s Manual U14826EJ5V0UD
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CHAPTER 6 PORT FUNCTIONS
6.1 Port Functions
The
µ
PD789860, 789861 Subseries is provided with the ports shown in Table 6-1. These ports enable several
types of control.
These ports, while originally designed as digital input/output ports, have alternate functions. For the alternate
functions, see
CHAPTER 3 PIN FUNCTIONS
.
Table 6-1. Port Functions
Name Pin
Name
Function
Port 0
P00 to P07
I/O port. Input/output can be specified in 1-bit units.
Port 2
P20, P21
I/O port. Input/output can be specified in 1-bit units.
Port 4
P40 to P43
Input-only port. Mask ROM versions can specify an on-chip pull-up resistor
by means of the mask option.
6.2 Port Configuration
Ports include the following hardware.
Table 6-2. Configuration of Port
Item Configuration
Control registers
Port mode registers (PMm: m = 0, 2)
Ports
Total: 14 (CMOS I/O: 10, CMOS input: 4)
Pull-up resistors
Mask ROM version: 4 (mask option control only)
EEPROM version:
None