NEC mPD789426 Series, User Manual

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CHAPTER 4 PORT FUNCTIONS
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User’s Manual U15075EJ1V0UM00
Table 4-3. Port Mode Register and Output Latch Settings When Using Alternate Functions
Alternate Function
Pin Name
Name I/O
PMxx Pxx
P00 to P03 KR0 to KR3 Input 1 x
P26 TO90 Output 0 0
INTP0 Input 1 x P30
CPT90 Input 1 x
INTP1 Input 1 x
TO50 Output 0 0
P31
TMI60 Input 1 x
INTP2 Input 1 x P32
TO60 Output 0 0
INTP3 Input 1 x P33
TO61 Output 0 0
P60 to P65 ANI0 to ANI5 Input 1 x
Caution When port 2 is used as a serial interface pin, the I/O latch or output latch must be set according
to its function. For the setting method, see Table 12-2 Settings of Serial Interface 20 Operating
Mode.
Remark x: don’t care
PMxx: Port mode register
Pxx: Port output latch
(2) Pull-up resistor option register 0 (PU0)
Pull-up resistor option register 0 (PU0) sets whether on-chip pull-up registers are used on ports 0 and 1 or
not.
On the port specified to use an on-chip pull-up resistor by PU0, the pull-up resistor can be internally used
only for the bits set in the input mode. No on-chip pull-up resistors can be used for the bits set in the output
mode regardless of the setting of PU0. This also applies to cases when the pins are used for alternate
functions.
PU0 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets PU0 to 00H.
Figure 4-19. Format of Pull-Up Resistor Option Register 0
Pm on-chip pull-up resistor selection
(m = 0, 1)
0 0 0 0 0 0 PU01 PU00 PU0
Address After reset R/W
FFF7H 00H R/W
7 6 5 4 3 2 <1> <0>
PU0m
0
1
On-chip pull-up resistor not used
On-chip pull-up resistor used
Symbol
Caution Bits 2 to 7 must be set to 0.