Renesas rl78 User Manual
RL78/G1A
CHAPTER 4 PORT FUNCTIONS
R01UH0305EJ0200 Rev.2.00
109
Jul 04, 2013
4.3.5 Port output mode registers (POMxx)
These registers set the output mode in 1-bit units.
N-ch open drain output (V
DD
tolerance
Note 1
/EV
DD
tolerance
Note 2
) mode can be selected during serial communication with
an external device of the different potential, and for the SDA00, SDA01, SDA10, SDA11, SDA20, and SDA21 pins during
simplified I
2
C communication with an external device of the same potential.
In addition, POMxx register is set with PUxx register, whether or not to use the on-chip pull-up resistor.
These registers can be set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation clears these registers to 00H.
Caution An on-chip pull-up resistor is not connected to a bit for which N-ch open drain output (V
DD
tolerance
Note 1
/EV
DD
tolerance
Note 2
) mode (POMmn = 1) is set.
Figure 4-5. Format of Port Input Mode Register
Symbol
7 6 5 4 3 2 1 0
Address
After
reset
R/W
POM0 0
0 0
POM04
POM03
POM02
0 0 F0050H 00H R/W
POM1
0
0
POM15 POM14 POM13
POM12
POM11
POM10
F0051H 00H R/W
POM5
0 0 0 0 0 0 0
POM50
F0055H
00H
R/W
POM7 0
0
0 POM74 0
0 POM71
0 F0057H 00H R/W
POMmn
Pmn pin output mode selection
(m = 0, 1, 5, 7; n = 0 to 5)
0
Normal output mode
1
N-ch open-drain output (V
DD
tolerance
Note 1
/EV
DD
tolerance
Note 2
) mode
Notes 1. For 25- to 48-pin products
2. For 64-pin products
Caution Be sure to set bits that are not mounted to their initial values.
<R>
<R>
<R>
<R>