Samsung C8278X User Manual

 

 

 

The S3C8275X/C8278X/C8274X microcontroller has seven bit-programmable I/O ports, P0

−P6. Port 0−port 5 are 

8-bit ports, port 6 is 4-bit. This gives a total of 52 I/O pins. Each port can be flexibly configured to meet application 
design requirements. 

The CPU accesses ports by directly writing or reading port registers. No special I/O instructions are required. All 
ports of the S3C8275X/C8278X/C8274X can be configured to input or output mode. P2

−P6 are shared with LCD 

signals. 

Table 9-1 gives you a general overview of S3C8275X/C8278X/C8274X I/O port functions. 

0 

1-bit programmable I/O port. 
Schmitt trigger input or push-pull, open-drain output and software assignable pull-ups. 
Alternatively P0.0

−P0.2 can be used as input for external interrupts INT and P0.3-P0.7 can be 

used as T1CLK, TAOUT, TBOUT, CLKOUT, and BUZ. 

1 

1-bit programmable I/O port. 
Schmitt trigger input or push-pull, open-drain output and software assignable pull-ups. 
Alternatively P1.3

−P1.7 can be used as input for external interrupts INT and P1.0−P1.2 can be 

used as SCK, SO, and SI. 

2 

1-bit programmable I/O port. 
Input or push-pull, open-drain output and software assignable pull-ups. 
Alternatively P2 can be used as outputs for LCD segment signals. 

3 

1-bit programmable I/O port. 
Input or push-pull, open-drain output and software assignable pull-ups. 
Alternatively P3 can be used as outputs for LCD segment signals. 

4 

1-bit programmable I/O port. 
Input or push-pull output and software assignable pull-ups. 
Alternatively P4 can be used as outputs for LCD segment signals. 

5 

1-bit programmable I/O port. 
Input or push-pull output and software assignable pull-ups. 
Alternatively P5 can be used as outputs for LCD segment signals. 

6 

1-bit programmable I/O port. 
Input or push-pull output and software assignable pull-ups.   
Alternately P6.0

−P6.3 can be used as outputs for LCD common signals.