Samsung C8274X Manual De Usuario
S3C8275X/F8275X/C8278X/F8278X/C8274X/F8274X
I/O
PORTS
9-15
PORT 4
Port 4 is an 8-bit I/O port with individually configurable pins. Port 4 pins are accessed directly by writing or reading
the port 4 data register, P4 at location F4H in set 1, bank 0. P4.0-P4.7 can serve as inputs (with or without pull-
up), as push-pull output or you can be configured the following functions.
the port 4 data register, P4 at location F4H in set 1, bank 0. P4.0-P4.7 can serve as inputs (with or without pull-
up), as push-pull output or you can be configured the following functions.
• Low-nibble pins (P4.0-P4.3): SEG15-SEG12
• High-nibble pins (P4.4-P4.7): SEG11-SEG8
• High-nibble pins (P4.4-P4.7): SEG11-SEG8
Port 4 Control Registers (P4CONH, P4CONL)
Port 4 has two 8-bit control registers: P4CONH for P4.4-P4.7 and P4CONL for P4.0-P4.3. A reset clears the
P4CONH and P4CONL registers to "00H", configuring all pins to input mode. You use control registers setting to
select input (with or without pull-up) or push-pull output mode and enable the alternative functions.
P4CONH and P4CONL registers to "00H", configuring all pins to input mode. You use control registers setting to
select input (with or without pull-up) or push-pull output mode and enable the alternative functions.
When programming this port, please remember that any alternative peripheral I/O function you configure using the
port 4 control registers must also be enabled in the associated peripheral module.
port 4 control registers must also be enabled in the associated peripheral module.
Port 4 Control Register, High Byte (P4CONH)
E9H, Set 1, Bank 1, R/W
.7
.6
.5
.4
.3
.2
.1
.0
MSB
LSB
P4.5/SEG10
P4.4/SEG11
P4CONH bit-pair pin configuration settings:
00
01
10
11
Push-pull output mode
Alternative function (SEG8-SEG11)
Input with pull-up resistor
Input mode
P4.7/SEG8
P4.6/SEG9
Figure 9-19. Port 4 High-Byte Control Register (P4CONH)