P89LPC921 datasheet(26/45 Pages) PHILIPS

Part #	P89LPC921

Description	8-bit microcontrollers with two-clock 80C51 core 2 kB/4 kB/8 kB 3 V low-power Flash with 256-byte data RAM

PDF	45 Pages

Scroll/Zoom	100%

Manufacturer	PHILIPS [NXP Semiconductors]

Direct Link	http://www.nxp.com

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26 / 45 page

Philips Semiconductors

P89LPC920/921/922

8-bit microcontrollers with two-clock 80C51 core

Product data

Rev. 06 — 21 November 2003

26 of 45

9397 750 12285

8.19 I2C-bus serial interface

I2C-bus uses two wires (SDA and SCL) to transfer information between devices

connected to the bus, and it has the following features:

• Bidirectional data transfer between masters and slaves

• Multimaster bus (no central master)

• Arbitration between simultaneously transmitting masters without corruption of

serial data on the bus

• Serial clock synchronization allows devices with different bit rates to communicate

via one serial bus

• Serial clock synchronization can be used as a handshake mechanism to suspend

and resume serial transfer

• The I2C-bus may be used for test and diagnostic purposes.

A typical I2C-bus conﬁguration is shown in Figure 8. The P89LPC920/921/922 device

provides a byte-oriented I2C-bus interface that supports data transfers up to 400 kHz.

Fig 8.

I2C-bus conﬁguration.

OTHER DEVICE

WITH I2C-BUS

INTERFACE

SDA

SCL

OTHER DEVICE

WITH I2C-BUS

INTERFACE

P1.3/SDA

P1.2/SCL

P89LPC920/921/922

I2C-BUS

002aaa420

P89LPC921 Datasheet(PDF) 26 Page - NXP Semiconductors