S3C84E5/C84E9/P84E9 I/O PORTS
9-1
9 I/O PORTS
OVERVIEW
The S3C84E5/C84E9/P84E9 microcontroller has seven bit-programmable I/O ports, P0P4. This gives a total of 36
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.
Table 9-1 gives you a general overview of the S3C84E5/C84E9/P84E9 I/O port functions.
Table 9-1. S3C84E5/C84E9/P84E9 Port Configuration Overview
Port Configuration Options
0 Bit programmable port; input or output mode selected by software; input or push-pull output. Software
assignable pull-up resistor.
Alternately, P0.0P0.7 can be used as I/O for Timer A, Timer 1(0,1). P0.0 and P0.1 can alternately be
used for subsystem oscillator in/out mode selected by software
1 Bit programmable port; input or output mode selected by software; input or push-pull output. Software
assignable pull-up resistor.
Alternatively, P1.0P1.5 can be used as Timer A, Timer 1(0), UART, Watch Timer Buzzer output
2 Bit programmable port; input or output mode selected by software; input or push-pull output. Software
assignable pull-up.
Alternately, P2.0P2.7 can be used as inputs for external interrupts INT0INT7. (with noise filters and
interrupt controller)
3 Bit programmable port; input or output mode selected by software; input or push-pull output. Software
assignable pull-up.
Alternately, P3.0P3.7 can be used as analog inputs for A/D converter modules.
4 Bit programmable port; input or output mode selected by software; input or push-pull output. Software
assignable pull-up.
Alternatively, P4.0P4.5 can be used as Timer B, inputs for external interrupts INT8INT10. (with noise
filters and interrupt controller)