NXP Semiconductors
P89LPC933/934/935/936
8-bit microcontroller with accelerated two-clock 80C51 core
8.21 I2C-bus serial interface
The 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
• Multi master 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 15. The P89LPC933/934/935/936
device provides a byte-oriented I2C-bus interface that supports data transfers up to
400 kHz.
I2C-bus
RP
RP
P1.3/SDA P1.2/SCL
P89LPC935
OTHER DEVICE
WITH I2C-BUS
INTERFACE
Fig 15. I2C-bus configuration
SDA
SCL
OTHER DEVICE
WITH I2C-BUS
INTERFACE
002aab082
P89LPC933_934_935_936
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 8 — 12 January 2011
© NXP B.V. 2011. All rights reserved.
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