UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 61

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

(3) P20 to P27 (Port 2) ... Input
Port 2 is an 8-bit input-only port. P22 to P27 incorporate a software programmable pull-up resistor. As well as operating
as an input port, port 2 pins also operate as control signal input pins, such as external interrupt signal pins (see Table
2-2). All 8 pins are Schmitt-triggered inputs to prevent misoperation due to noise.
Also, pin P25 can also be made to function as a serial clock output pin by selecting the external clock as “serial operation
enabled” with the clocked serial interface mode register 1 (CSIM1).
(a) Port mode
(b) Control signal output mode
P10 and P11 operate as port mode pins when the EN0 and EN1 bits of the PWM control (PWMC) register are cleared
(0), and P12 to P14 do the same when the relevant bits of the port 1 mode control (PMC1) register are cleared (0),
and P15 to P17 always operate as port mode pins. Input/output can be specified bit-wise by means of the port 1 mode
register (PM1).
P10 and P11 operate as PWM signal output pins when the EN0 and EN1 bits, respectively, of the PWM control
(PWMC) register are set (1).
P12 to P14 can be set as control pins bit-wise by setting the port 1 mode control (PMC1) register.
(i)
(ii)
(iii) TxD2/SO2
ASCK2/SCK2
ASCK2 is the asynchronous serial interface baud rate clock input pin.
SCK2 is the serial clock input/output pin (in 3-wire serial I/O2 mode).
RxD2/SI2
RxD2 is the asynchronous serial interface serial data input pin.
SI2 is the serial data input pin (in 3-wire serial I/O2 mode).
TxD2 is the asynchronous serial interface serial data output pin.
SO2 is the serial data output pin (in 3-wire serial I/O2 mode).
CHAPTER 2 PIN FUNCTIONS
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