Samsung S3C80M4/F80M4 User Manual page 203

S3C80M4/F80M4
9
I/O PORTS
OVERVIEW
The S3C80M4/F80M4 microcontroller has two bit-programmable I/O ports, P0–P1. The port 0 is a 8-bit port, the
port 1 is a 7-bit port. This gives a total of 15 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 S3C80M4/F80M4 I/O port functions.
Port
0 1-bit programmable I/O port.
Schmitt trigger input or push-pull output mode selected by software; software assignable pull-ups.
P0.0–P0.3 can be used as inputs for external interrupts INT0–INT3
(with interrupt enable and pending control). Alternately P0.6 can be used as PWM.
1 1-bit programmable I/O port.
Input or push-pull, open-drain output mode selected by software; software assignable pull-ups.
Alternately P1.0, P1.0, P1.6 can be used as T0OUT, T0CLK, CLKOUT.
PORT DATA REGISTERS
Table 9-2 gives you an overview of the register locations of all four S3C80M4/F80M4 I/O port data registers. Data
registers for ports 0 and 1 have the general format shown in Figure 9-1.
Register Name
Port 0 data register
Port 1 data register
Table 9-1. S3C80M4/F80M4 Port Configuration Overview
Table 9-2. Port Data Register Summary
Mnemonic Decimal
P0
P1
Configuration Options
Hex
224 E0H
225 E1H
I/O PORTS
Location R/W
Set 1, Bank 0 R/W
Set 1, Bank 0 R/W
9-1