17. I2C - Inter-Integrated Circuit Interface
4
3
2
1
0
Gecko Device
I
2
C master/slave
Other I
2
C
master
Other I
2
C
slave
V
DD
I
2
C
EEPROM
SDA
SCL
Quick Facts
What?
The I
2
C interface allows communication on I
2
C-
buses with the lowest energy consumption possible.
Why?
I
2
C is a popular serial bus that enables communica-
tion with a number of external devices using only
two I/O pins.
How?
With the help of DMA, the I
2
C interface allows I
2
C
communication with minimal CPU intervention. Ad-
dress recognition is available in all energy modes
(except EM4), allowing the MCU to wait for data on
the I
2
C-bus with sub-µA current consumption.
17.1 Introduction
The I
2
C module provides an interface between the MCU and a serial I
2
C-bus. It is capable of acting as both a master and a slave and
supports multi-master buses. Standard-mode, fast-mode and fast-mode plus speeds are supported, allowing transmission rates all the
way from 10 kbit/s up to 1 Mbit/s. Slave arbitration and timeouts are also provided to allow implementation of an SMBus compliant sys-
tem. The interface provided to software by the I
2
C module allows precise control of the transmission process and highly automated
transfers. Automatic recognition of slave addresses is provided in all energy modes (except EM4).
17.2 Features
• True multi-master capability
• Support for different bus speeds
• Standard-mode (Sm) bit rate up to 100 kbit/s
• Fast-mode (Fm) bit rate up to 400 kbit/s
• Fast-mode Plus (Fm+) bit rate up to 1 Mbit/s
• Arbitration for both master and slave (allows SMBus ARP)
• Clock synchronization and clock stretching
• Hardware address recognition
• 7-bit masked address
• General call address
• Active in all energy modes (except EM4)
• 10-bit address support
• Error handling
• Clock low timeout
• Clock high timeout
• Arbitration lost
• Bus error detection
• Separate receive/ transmit 2-level buffers, with additional separate shift registers
• Full DMA support
Reference Manual
I2C - Inter-Integrated Circuit Interface
silabs.com
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