NEC PD78F9488 - Manual (Page 112)

CHAPTER 6 16-BIT TIMER 20
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User’s Manual U15331EJ4V1UD
(2) Port mode register 3 (PM3)
This register is used to set the I/O mode of port 3 in 1-bit units.
When using the P33/INTP3/CPT20/TO20 pin as a capture input (CPT20), set PM33 to 1. When using the
above pin as a timer output (TO20), set the PM33 and P33 output latches to 0.
PM3 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets this register to FFH.
Figure 6-3. Format of Port Mode Register 3
Symbol 7 6 5 4 3 2 1 0 Address After reset R/W
PM3 1 1 1 PM34 PM33 PM32 PM31 PM30 FF23H FFH R/W
PM33 Selection of P33 pin I/O mode
0 Output mode (output buffer is on)
1 Input mode (output buffer is off)