GD32W51x User Manual
629
Figure 19-1. I2C module block diagram
Receive
Data
Register
A
P
B
B
u
s
SDA Controller
CRC Calculation /
Check
PEC register
SCL Controller
Timing and
Control Logic
Control Registers
Status Flags
DMA/ Interrupts
SMBA
Analog
Noise
filter
Digital
Noise
filter
Analog
Noise
filter
Digital
Noise
filter
Transmit
Data
Register
Shift
Register
Wakeup on
address macth
SDA
SCL
Table 19-1. Definition of I2C-bus terminology (refer to the I2C specification of Philips
semiconductors)
Term
Description
Transmitter
the device w hich sends data to the bus
Receiver
the device w hich receives data from the bus
Master
the device w hich initiates a transf er, generates clock signals and terminates a
transfer
Slave
the device addressed by a master
Multi-master
more than one master can attempt to control the bus at the same time w ithout
corrupting the message
Arbitration
procedure to ensure that, if more than one master tries to control the bus
simultaneously, only one is allow ed to do so and the w inning ma
ster’s
message is not corrupted
19.3.1.
Clock requirements
The I2C clock is independent of the PCLK frequency, so that the I2C can be operated
independently.
This I2C clock (I2CCLK) can be selected from the following three clock sources:
PCLK1: APB1 clock (default value)
IRC16M: internal 16 MHz RC
SYSCLK: system clock
The I2CCLK period t
I2CCLK
must match the conditions as follows:
t
I2CCLK
< (t
LOW
- t
filters
) / 4
t
I2CCLK
< t
HIGH