UPD784938 Datasheet, PDF (148/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 6 PORT FUNCTIONS
6.5.2 I/O mode/control mode setting
The port 3 input/output mode is set for each pin by means of the port 3 mode register (PM3) as shown in Figure 6-30.
In addition to their input/output port function, port 3 pins also have an alternate function as various control signal pins, and
the control mode is specified by setting the port 3 mode control register (PMC3) as shown in Figure 6-31.
Figure 6-30. Port 3 Mode Register (PM3) Format
PM3
7
6
5
4
3
2
1
0 Address After reset R/W
PM37 PM36 PM35 PM34 PM33 PM32 PM31 PM30 0FF23H
FFH
R/W
PM3n P3n Pin Input/Output Mode Specification
(n = 0 to 7)
0 Output mode (output buffer on)
1 Intput mode (output buffer off)
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Preliminary User’s Manual U13987EJ1V0UM00