CHAPTER 4 PORT FUNCTIONS
(c) Port 4 mode control register (PMC4)
This is an 8-bit register that specifies the port mode/control mode.
This register can be read/written in 8-bit or 1-bit units.
After Reset: 00H
R/W
0
Address: FFFFF448H
PMC4
0
0
0
0
PMC42 PMC41 PMC40
PMC42
Specification of P42 pin operation mode
Specification of P41 pin operation mode
Specification of P40 pin operation mode
0
1
I/O port
SCK00 I/O
PMC41
0
1
I/O port
SO00 output
PMC40
0
1
I/O port
SI00 input
(d) Port 4 function register (PF4)
This is an 8-bit register that specifies normal output/N-ch open-drain output.
This register can be written in 8-bit or 1-bit units.
After Reset: 00H
R/W
0
Address: FFFFFC68H
PF4
0
0
0
0
PF42
PF41
0
PF4n
Control of normal output/N-ch open-drain output
0
1
Normal output
N-ch open-drain output
Caution When using P41 and P42 as N-ch open-drain-output alternate-function pins, set
in the following sequence.
Be sure to set the port latch to 1 before setting the pin to N-ch open-drain output.
P4n bit = 1 → PF4n bit = 1 → PMC4n bit = 1
User’s Manual U15862EJ3V0UD
167
NEC [ NEC ]
