LS_I2C controller
RM0082
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Doc ID 018672 Rev 1
Figure 61.
I
2
C controller functional block diagram
28.3
Main functions description
This chapter describes the functional behavior of I2C in more detail.
28.3.1 APB
interface
The host processor accesses data, control and status information on the I
2
C controller
through the APB Slave Interface. The I
2
C controller has 16 bit APB data bus width.
28.3.2 I
2
C protocols
According to the I
2
C-bus specification, the I
2
C controller implements the following protocols:
●
START and STOP Condition Protocol,
●
Addressing Slave Protocol,
●
Transmitting and Receiving Protocol,
●
START Byte Transfer Protocol.
START and STOP condition protocol
When the bus is IDLE, both the SCL (serial clock) and SDA (serial data) signals are pulled
high through external pull-up resistors on the bus.
When the i2c master wants to start a transmission on the bus, it issues a START condition
which is defined as a high-to-low transition of the SDA signal while SCL is high (see
).
When the i2c master wants to terminate the transmission, it issues a STOP condition which
is defined as a low-to-high transition of the SDA signal while SCL is high.
When data is being transmitted on the bus, the SDA line must be stable when SCL is high.
I2C Debug
APB Slave
Interface
I2C Master/
Slave
Interrupts
RX Filter
Clock
Generator
DMA
Interface
TX -FIFO
RX -FIFO
I2C Controller