Registers Controlling Port Function - NEC MuPD78F0132H User Manual

8-bit single-chip microcontrollers, 78k0/ke1plus

Table of Contents

4.3 Registers Controlling Port Function

Port functions are controlled by the following three types of registers.

• Port mode registers (PM0, PM1, PM3 to PM7, PM12, PM14)

• Port registers (P0 to P7, P12 to P14)

• Pull-up resistor option registers (PU0, PU1, PU3 to PU5, PU7, PU12, PU14)

(1) Port mode registers (PM0, PM1, PM3 to PM7, PM12, and PM14)

These registers specify input or output mode for the port in 1-bit units.

These registers can be set by a 1-bit or 8-bit memory manipulation instruction.

RESET input sets these registers to FFH.

When port pins are used as alternate-function pins, set the port mode register and output latch as shown in Table

Output mode (output buffer on)

Input mode (output buffer off)

CHAPTER 4 PORT FUNCTIONS

Figure 4-21. Format of Port Mode Register

Pmn pin I/O mode selection

(m = 0, 1, 3 to 7, 12, 14; n = 0 to 7)

User's Manual U16899EJ2V0UD