P89LPC904FD datasheet(6/41 Pages) PHILIPS

6 / 41 page

Philips Semiconductors

P89LPC904

8-bit microcontrollers with two-clock accelerated 80C51 core

Preliminary data

Rev. 02 — 25 June 2004

6 of 41

9397 750 13521

P1.0 to P1.5

3, 4, 5

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 Section 8.13.1 “Port conﬁgurations” and Table 8 “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:

I/O

P1.0 — Port 1 bit 0.

TxD — Serial port transmitter data.

I/O

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.

VSS

Ground: 0 V reference.

VDD

Power Supply: This is the power supply voltage for normal operation as well as Idle

and Power-down modes.

Table 3:

P89LPC904 pin description…continued

Symbol

Type

Description

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