
Philips Semiconductors
P89LPC906/907/908
8-bit microcontrollers with two-clock 80C51 core
Product data
Rev. 05 — 17 December 2004
11 of 51
9397 750 14467
Koninklijke Philips Electronics N.V. 2004. All rights reserved.
P1.0 to P1.5
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
Section 8.11.1 “Port configurations”
and
Table 13 “DC
electrical characteristics”
for details. P1.5 is input only.
All pins have Schmitt triggered inputs.
Port 1 also provides various special functions as described below:
P1.0 —
Port 1 bit 0.
TxD —
Serial port transmitter data.
P1.1 —
Port 1 bit 1.
RxD —
Serial port receiver data.
P1.5 —
Port 1 bit 5 (input only).
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-System
Programming mode.
Ground:
0 V reference.
Power Supply:
This is the power supply voltage for normal operation as well as Idle
and Power-down modes.
5
I/O
O
I/O
I
I
I
4
1
V
SS
V
DD
2
6
I
I
Table 5:
Symbol
P89LPC908 pin description
…continued
Pin
Type
Description