S3F80P5_UM_ REV1.00 I/O PORTS
9 I/O PORTS
OVERVIEW
The S3F80P5 microcontroller has four bit-programmable I/O ports, P0, P1, P2, P3. Two ports, P0 and P1, are 8-
bit ports and P2 is a 1-bit port and P3 is a 2-bit port. This gives a total of 19 I/O pins.
Each port is bit-programmable and 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.
For IR applications, port0, port1 are usually configured to the keyboard matrix, port2 is normal I/O pin and port 3
is used to IR drive pins.
Table 9-1, 9-2 and 9-3 give you a general overview of S3F80P5 I/O port functions.
9-1