S3C8245/P8245/C8249/P8249 I/O PORTS
9-1
9I/O PORTS
OVERVIEW
The S3C8245/C8249 microcontroller has two nibble-programmable and four bit-programmable I/O ports,
P0–P5. The port 3 is a 5-bit port and the others are 8-bit ports. This gives a total of 45 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 S3C8245/C8249 I/O port functions.
Table 9-1. S3C8245/C8249 Port Configuration Overview
Port Configuration Options
01-bit programmable I/O port.
Schmitt trigger input or output mode selected by software; software assignable pull-up.
P0.0–P0.7 can be used as inputs for external interrupts INT0–INT7
(with noise filter and interrupt control).
11-bit programmable I/O port.
Input or output mode selected by software; open-drain output mode can be selected by software;
software assignable pull-up.
Alternately P1.0–P1.7 can be used as SI, SO, SCK, BUZ, T1CAP, T1CLK, T1OUT, T1PWM.
21-bit programmable I/O port.
Normal input and AD input or output mode selected by software;
software assignable pull-up.
31-bit programmable I/O port.
Input or push-pull output with software assignable pull-up.
Alternately P3.0–P3.3 can be used as TACAP, TACLK, TAOUT, TAPWM, TBPWM.
41-bit programmable I/O port.
Push-pull or open drain output and input with software assignable pull-up.
P4.0–P4.7 can alternately be used as outputs for LCD SEG.
51-bit programmable I/O port.
Push-pull or open drain output and input with software assignable pull-up.
P5.0–P5.7 can alternately be used as outputs for LCD SEG.