GD32A50x User Manual
510
Analog filter delay is maximum 260ns. Digital filter delay is
DNF[3:0]×t
I2CCLK
.
The period of PCLK clock
t
PCLK
match the conditions as follows:
t
PCLK
<4/3*t
SCL
with:
t
SCL
: the period of SCL
Note:
When the I2C kernel is provided by PCLK, this clock must match the conditions for
t
I2CCLK
.
20.3.2.
I2C communication flow
An I2C device is able to transmit or receive data whether it’s a master or a slave, thus, there’re
4 operation modes for an I2C device:
Slave transmitter
Slave receiver
Master transmitter
Master receiver
Data validation
The data on the SDA line must be stable during the HIGH period of the clock. The HIGH or
LOW state of the data line can only change when the clock signal on the SCL line is LOW
(see
). One clock pulse is generated for each data bit transferred.
Figure 20-2. Data validation
SDA
SCL
START and STOP signal
All transactions begin with a START and are terminated by a STOP (see
). A HIGH to LOW transition on the SDA line while SCL is HIGH defines a
START signal. A LOW to HIGH transition on the SDA line while SCL is HIGH defines a STOP
signal.