Samsung 8-Bit CMOS Microcontroller Microcassette Recorder User Manual


 
S3C9228/P9228 I/O PORTS
9-15
PORT 5
Port 5 is an 8-bit I/O port with individually configurable pins. Port 5 pins are accessed directly by writing or
reading the port 5 data register, P5 at location E9H in page 0. P5.0-P5.7 can serve as inputs or as push-pull,
open-drain outputs. You can configure the following alternative functions with LCD port control register, LPOT:
Low-nibble pins (P5.0-P5.3): SEG12-SEG15
High-nibble pins (P5.4-P5.7): SEG16-SEG19, COM4-COM7
Port 5 Control Registers (P5CONH, P5CONL)
Port 5 has two 8-bit control registers: P5CONH for P5.4-P5.7 and P4CONL for P5.0-P5.3. A reset clears the
P5CONH and P5CONL registers to "00H", configuring all pins to input mode. You use control registers setting to
select input or output mode.
Port 5 Control Register, High Byte (P5CONH)
FBH, Page 0, R/W
.7 .6 .5 .4 .3 .2 .1 .0MSB LSB
P5.5/SEG17/COM6
P5.4/SEG16/COM7
P5CONH bit-pair pin configuration settings:
00
01
10
11
N-channel open-drain output mode
Input mode with pull-up
Push-pull output mode
Input mode
P5.6/SEG18/COM5
P5.7/SEG19/COM4
Figure 9-21. Port 5 High-Byte Control Register (P5CONH)
Port 5 Control Register, Low Byte (P5CONL)
FCH, Page 0, R/W
.7 .6 .5 .4 .3 .2 .1 .0MSB LSB
P5.1/SEG13 P5.0/SEG12
P5CONL bit-pair pin configuration settings:
00
01
10
11
N-channel open-drain output mode
Input mode with pull-up
Push-pull output mode
Input mode
P5.2/SEG14P5.3/SEG15
Figure 9-22. Port 5 Low-Byte Control Register (P5CONL)