p89lpc904 NXP Semiconductors, p89lpc904 Datasheet - Page 6

• Manufacturer Part Number: p89lpc904
• Description: 8-bit Microcontrollers With Two-clock Accelerated 80c51 Core 1 Kb 3 V Byte-erasable Flash With 8-bit A/d Converter
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Table 3:
9397 750 13521
Preliminary data
Symbol
P1.0 to P1.5
V
V
SS
DD
P89LPC904 pin description
Pin
3, 4, 5
5
3
4
8
1
Type
O
I
I
I/O
I/O
I
I
I
Description
Port 1: Port 1 is an I/O port with a user-configurable output type. 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
electrical characteristics”
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.
…continued
Rev. 02 — 25 June 2004
8-bit microcontrollers with two-clock accelerated 80C51 core
Section 8.13.1 “Port configurations”
for details. P1.5 is input only.
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
P89LPC904
and
Table 8 “DC
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