SAM3X8E Atmel Corporation, SAM3X8E Datasheet - Page 711

• Manufacturer Part Number: SAM3X8E
• Manufacturer: Atmel Corporation

33. Two-wire Interface (TWI)
33.1
33.2
11057A–ATARM–17-Feb-12
11057A–ATARM–17-Feb-12
Description
Embedded Characteristics
The Atmel Two-wire Interface (TWI) interconnects components on a unique two-wire bus, made
up of one clock line and one data line with speeds of up to 400 Kbits per second, based on a
byte-oriented transfer format. It can be used with any Atmel Two-wire Interface bus Serial
EEPROM and I²C compatible device such as Real Time Clock (RTC), Dot Matrix/Graphic LCD
Controllers and Temperature Sensor, to name but a few. The TWI is programmable as a master
or a slave with sequential or single-byte access. Multiple master capability is supported. 20
Arbitration of the bus is performed internally and puts the TWI in slave mode automatically if the
bus arbitration is lost.
A configurable baud rate generator permits the output data rate to be adapted to a wide range of
core clock frequencies.
Below,
a full I2C compatible device.
Table 33-1.
Note:
I2C Standard
Standard Mode Speed (100 KHz)
Fast Mode Speed (400 KHz)
7 or 10 bits Slave Addressing
START BYTE
Repeated Start (Sr) Condition
ACK and NACK Management
Slope control and input filtering (Fast mode)
Clock stretching
Multi Master Capability
• 2 x TWI
• Compatible with Atmel Two-wire Interface Serial Memory and I²C Compatible Devices
• One, Two or Three Bytes for Slave Address
• Sequential Read-write Operations
• Master, Multi-master and Slave Mode Operation
• Bit Rate: Up to 400 Kbits
• General Call Supported in Slave mode
• SMBUS Quick Command Supported in Master Mode
• Connection to Peripheral DMA Controller (PDC) Channel Capabilities Optimizes Data
Transfers in Master Mode Only
– One Channel for the Receiver, One Channel for the Transmitter
– Next Buffer Support
Table 33-1
1. START + b000000001 + Ack + Sr
(1)
Atmel TWI compatibility with i2C Standard
lists the compatibility level of the Atmel Two-wire Interface in Master Mode and
Atmel TWI
Supported
Supported
Supported
Not Supported
Supported
Supported
Not Supported
Supported
Supported
SAM3X/A
SAM3X/A
(Note:)
711
711