
AT32F413
Series Reference Manual
2022.06.27
Page 120
Rev 2.00
11
I
2
C interface
11.1 I
2
C introduction
I2C (inter-integrated circuit) bus interface manages the communication between the microcontroller and
serial I
2
C bus. It supports master and slave modes, with up to 400 kbit/s of communication speed.
11.2 I
2
C main features
I2C bus
―
Master and slave modes
―
Multimaster capability
―
Stand speed (100 kHz) and fast speed (400 kHz)
―
7-bit and 10-bit address modes
―
Broadcast call mode
―
Status flag
―
Error flag
―
Clock stretching capability
―
Communication event interrupts
―
Error interrupts
Support DMA transfer
Support partial SMBus2.protocol
―
PEC generation and verification
―
SMBus reminder function
―
ARP(address resolution protocol)
―
Timeout mechanism
PMBus
11.3 I
2
C function overview
I
2
C bus consists of a data line (SDA) and clock line (SCL). It can achieve a maximum of 100 kHz speed
in standard mode, while up to 400kHz in fast mode. A frame of data transmission begins with a Start
condition and ends with a Stop condition. The bus is kept in busy state after receiving the Start condition,
and becomes idle as long as it receives the Stop condition.
Start condition: When SCL is set high, SDA switches from high to low
Stop condition: When SCL is set high, SDA switches from low to high.
Figure 11-1 I2C bus protocol
SDA
SCL
Start condition
Stop condition
8
9
2
1
MSB
ACK
3 to 7