BAT32G1x9 user manual | Chapter 19 Universal serial communication unit
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Rev.1.02
19.9.5
Calculation of the transfer rate
Simple I
2
C (IIC00, IIC01, IIC10, IIC11, IIC20, The transmission rate of IIC21, IIC30, IIC31)
communication can be calculated using the following calculation equation.
Note It is forbidden to set SDRmn[15:9]
to
"0000000B", and the setting value of SDRmn[15:9] must be greater than or
equal to "0000001B". The SCL signal output of simple I2C has a duty cycle of 50%. In the I2 C-bus specification,
the low-level width of the SCL signal is greater than the high-level width. Therefore, if set to 400kbps in fast mode
or 1Mbps in enhanced fast mode, the low level width of the SCL signal output is less than I2C The specification
value of the bus. SDRmn [15:9] must be set to meet the I2 C-bus specifications.
Note 1
Because the value of SDRmn[15:9] is the value of bit15~9 of the serial data register (SDRmn)
(0000001B~111111B). ), so it is 1 to 127.
2.m:unit number(m=0~2)n:channel number(n=0~3)mn=00~03, 10~11, 20~21
The operating clock
(f
MCK
)
depends on bit15 of the serial clock selection register m (SPSm) and the serial mode register
mn (SMRmn). (CKSmn bit).
(Transfer Rate)={Runtime Clock (
fMCK
)
Frequency} (SDRmn
÷
[15:9]+1)
÷
2