Samsung C8278X ユーザーズマニュアル

 

 

 

Port 2 is an 8-bit I/O port with individually configurable pins. Port 2 pins are accessed directly by writing or reading 
the port 2 data register, P2 at location F2H in set 1, Bank 0. P2.0-P2.7 can serve as inputs (with or without pull-
up), as outputs (push-pull or open-drain) or you can be configured the following functions. 

•  Low-nibble pins (P2.0-P2.3): SEG31−SEG28, V

BLDREF

 

•  High-nibble pins (P2.4-P2.7): SEG27−SEG24 

Port 2 has two 8-bit control registers: P2CONH for P2.4-P2.7 and P2CONL for P2.0-P2.3. A reset clears the 
P2CONH and P2CONL registers to "00H", configuring all pins to input mode. You use control registers setting to 
select input or output mode (push-pull or open-drain) and enable the alternative functions. 

When programming this port, please remember that any alternative peripheral I/O function you configure using the 
port 2 control registers must also be enabled in the associated peripheral module. 

Using the port 2 pull-up resistor control register, P2PUR (ECH, set 1, bank 0), you can configure pull-up resistors 
to individual port 2 pins. 

Port 2 Control Register, High Byte (P2CONH)

EAH, Set 1, Bank 0, R/W

.7

.6

.5

.4

.3

.2

.1

.0

MSB

LSB

P2.7/SEG24

P2CONH bit-pair pin configuration settings:

00

01

10

11

Alternative function (SEG24-SEG27)

P2.6/SEG25 P2.5/SEG26

P2.4/SEG27

Input mode

N-channel open-drain output mode

Push-pull output mode