NEC NEC PD78081(A), User Manual

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CHAPTER 4 PORT FUNCTIONS
4.3 Port Function Control Registers
The following two types of registers control the ports.
• Port mode registers (PM0, PM1, PM3, PM5, PM7, PM10)
• Pull-up resistor option register (PUOH, PUOL)
(1) Port mode registers (PM0, PM1, PM3, PM5, PM7, PM10)
These registers are used to set port input/output in 1-bit units.
PM0, PM1, PM3, PM5, PM7, PM10 are independently set with a 1-bit or 8-bit memory manipulation instruction
RESET input sets registers to FFH.
When port pins are used as the dual-function pins, set the port mode register and output latch according to
Table 4-3.
Cautions 1. P00 pin is input-only pin.
2. As port 0 has a dual function as external interrupt request input, when the port function
output mode is specified and the output level is changed, the interrupt request flag is
set. When the output mode is used, therefore, the interrupt mask flag should be set to
1 beforehand.