Philips P89LPC903 - Manual (Page 12)

Philips Semiconductors User’s Manual - Preliminary -
P89LPC901/902/903 GENERAL DESCRIPTION
2003 Dec 8
12
PIN DESCRIPTIONS - P89LPC901
MNEMONIC PIN NO. TYPE NAME AND FUNCTION
P0.0 - P0.6 6, 7 I/O Port 0: Port 0 is an I/O port with a user-configurable output types.
During reset Port 0 latches are configured in the input only
mode with the internal pullup disabled. The operation of port
0 pins as inputs and outputs depends upon the port
configuration selected. Each port pin is configured
independently. Refer to the section on I/O port
configuration and the DC Electrical Characteristics in the
Data Sheet for details.
The Keypad Interrupt feature operates with port 0 pins.
All pins have Schmitt triggered inputs.
Port 0 also provides various special functions as described below.
7 I/O P0.4 Port 0 bit 4.
I CIN1A Comparator positive input.
I KBI4 Keyboard Input 4.
6 I/O P0.5 Port 0 bit 5.
I CMPREFComparator reference (negative) input.
I KBI5 Keyboard Input 5.
P1.0 - P1.5 4,5 Port 1: Port 1 is an I/O port with a user-configurable output types.
During reset Port 1 latches are configured in the input only
mode with the internal pull-up disabled. The operation of the
configurable port 1 pins as inputs and outputs depends
upon the port configuration selected. Each of the
configurable port pins are programmed independently.
Refer to the section on I/O port configuration and the DC
Electrical Characteristics in the Data Sheet for details. P1.5
is input only.
All pins have Schmitt triggered inputs.
Port 1 also provides various special functions as described below.
5 I/O P1.2 Port 1 bit 2.
I/O T0 Timer/counter 0 external count input or overflow output.
4 I P1.5 Port 1 bit 5. (Input only)
I RST External Reset input during power-on or if selected via
UCFG1. When functioning as a reset input a low on this pin
resets the microcontroller, causing I/O ports and peripherals
to take on their default states, and the processor begins
execution at address 0. Also used during a power-on
sequence to force In-Circuit Programming mode.
P3.0 - P3.1 2, 3 I/O Port 3 Port 3 is an I/O port with a user-configurable output types.
During reset Port 3 latches are configured in the input only
mode with the internal pullup disabled. The operation of
port 3 pins as inputs and outputs depends upon the port
configuration selected. Each port pin is configured
independently. Refer to the section on I/O port
configuration and the DC Electrical Characteristics in the
Data Sheet for details.
All pins have Schmitt triggered inputs.
Port 3 also provides various special functions as described below:
3 I/O P3.0 Port 3 bit 0.