NEC 78K0 Series User Manual page 424

(7) Port mode register 6 (PM6)
This register sets the input/output of port 6 in 1-bit units.
When using the P60/SCL0 pin as clock I/O and the P61/SDA0 pin as serial data I/O, clear PM60 and PM61,
and the output latches of P60 and P61 to 0.
Set IICE0 (bit 7 of IIC control register 0 (IICC0)) to 1 before setting the output mode because the P60/SCL0
and P61/SDA0 pins output a low level (fixed) when IICE0 is 0.
PM6 is set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation sets PM6 to FFH.
Address: FF26H
Symbol 7
PM6 1
PM6n
0
1
424
CHAPTER 17 SERIAL INTERFACE IIC0
Figure 17-10. Format of Port Mode Register 6 (PM6)
After reset: FFH R/W
6 5
1 1
P6n pin I/O mode selection (n = 0 to 3)
Output mode (output buffer on)
Input mode (output buffer off)
Preliminary User's Manual U17260EJ3V1UD
4 3 2
1 PM63 PM62
1 0
PM61 PM60