UPD78F9418A NEC, UPD78F9418A Datasheet - Page 85

• Manufacturer Part Number: UPD78F9418A
• Description: (UPD7894xxA) 8-Bit Single Chip Microcontrollers
• Manufacturer: NEC

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4.3 Registers Controlling Ports
The following two registers control the ports.
• Port mode registers (PM0, PM2, PM4, PM5, PM8, and PM9)
• Pull-up resistor option registers (PU0 to PU2)
(1)
Note Set key return mode register 00 (KRM00) to 1 when using the alternate function (see 15.3 (6) Key return
Caution When port 2 is used for the serial interface, the I/O or output latch must be set according to the
Remark
Port mode registers (PM0, PM2, PM4, PM5, PM8, and PM9)
These registers are used to set port input/output in 1-bit units.
The port mode registers are independently set using a 1-bit or 8-bit memory manipulation instruction.
RESET input sets these registers to FFH.
When port pins are used as alternate-function pins, set the port mode register and output latch according to
Table 4-3.
Caution As port 2 has an alternate function as the external interrupt input, when the port function
Table 4-3. Port Mode Register and Output Latch Settings When Using Alternate Functions
mode register 00 (KRM00)).
P23
P24
P25
P26
P27
P40 to P45
P80 to P87
P90 to P93
Pin Name
function used. For the setting method, see Table 13-2 Operation Mode Settings of Serial
Interface 00.
x:
PMxx:
Pxx:
output mode is specified and the output level is changed, the interrupt request flag is set.
When the output mode is used, therefore, the interrupt mask flag should be set to 1
beforehand.
Note
Don’t care
Port mode register
Port output latch
CMPTOUT0
TO2
INTP0
TI0
INTP1
TI1
INTP2
TO5
INTP3
CPT5
KR0 to KR5
S27 to S20
S19 to S16
Name
Alternate Function
CHAPTER 4 PORT FUNCTIONS
User’s Manual U13952EJ3V0UD
Output
Output
Input
Input
Input
Input
Input
Output
Input
Input
Input
Output
Output
I/O
PMxx
0
0
1
1
1
1
1
0
1
1
1
0
0
Pxx
0
0
0
x
x
x
x
x
x
x
x
0
0
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