
CHAPTER 4 PORT FUNCTIONS
User’s Manual U15905EJ2V1UD
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(e) Port function register 9 (PF9)
This 16-bit register specifies normal output or N-ch open-drain output.
The PF9 register can be read or written only in 16-bit units. If the higher 8 bits of the PF9 register are used
as PF9H and the lower 8 bits as PF9L, however, PF9H and PF9L can be manipulated in 8-bit or 1-bit units.
PF9 (PF9HNote)
After reset: 0000H
R/W
Address: PF9 FFFFFC72H, PF9H FFFFFC73H
00
0
PF915
PF914
0
PF912
PF911
0
8
9
10
11
12
13
14
15
Normal output
N-ch open-drain output
PF9n
0
1
Controls normal output or N-ch open-drain output (n = 11, 12, 14, or 15)
Note
When reading or writing bits 8 to 15 of the PF9 register in 8-bit or 1-bit units, specify these bits as bits 0
to 7 of the PF9H register.
Cautions 1. The N-ch open-drain output voltage is the normal voltage, not the medium voltage.
2. PF9n = 1 is enabled only in the following cases. Otherwise, the setting is prohibited.
n = 1: SO2
n = 2: SCK2
n = 4: SO3
n = 5: SCK3
3. Follow the procedure below to set N-ch open drain.
<1> Set the P9n bit to 1.
<2> Set the PF9n bit to 1.
<3> Set the CSIE2 bit of the CSIM2 register or the CSIE3 bit of the CSIM3 register to 1.
<4> Set the PFC9n bit.
<5> Set the PMC9n bit to 1.