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AT32F413
Series Reference Manual
2022.06.27
Page 140
Rev 2.00
0: Data reception
1: Data transmission
Cleared by hardware when a Stop condition is received.
Bit 1
BUSYF
0x0
ro
Bus busy flag transmission mode
0: Bus idle
1: Bus busy
Set by hardware on detection of SDA/SCL low, and cleared
by hardware on detection of a Stop condition.
Bit 0
TRMODE
0x0
ro
Transmission mode
0: Slave mode
1: Master mode
Set by hardware when the GENSTART is set and a Start
condition is sent. Cleared by hardware when a Stop
condition is detected.
11.5.8 Clock control register (I2C_ CLKCTRL)
Bit
Register
Reset value
Type
Description
Bit 15
SPEEDMODE
0x0
rw
Speed mode selection
0: Standard mode (up to 100 kHz)
1: Fast mode (up to 400 kHz)
In fast mode, an accurate 400kHz clock is generated when
the I
2
C clock frequency is an integer multiple of 10MHz.
Bit 14
DUTYMODE
0x0
rw
Fast mode duty cycle
0: The ratio of High to low is 1:2.
1: The ratio of low to high is 9:16.
Bit 13: 12 Reserved
0x0
resd
Kept at its default value.
Bit 11: 0
SPEED
0x000
rw
I
2
C bus speed config
In standard mode:
High level= SPEED x T
I2C_CLK
Low level= SPEED x T
I2C_CLK
In fast mode:
DUTYMODE = 0:
High level= SPEED x T
I2C_CLK
x 1
Low level= SPEED x T
I2C_CLK
x 2
DUTYMODE = 1:
High level= SPEED x T
I2C_CLK
x 9
Low level= SPEED x T
I2C_CLK
x 16
The minimum value allowed in standard mode is 4. In fast
mode, the minimum value allowed is 1.
The CLKCTRL register can be configured only when the
I2C is disabled (I2CEN=0).
Note: The CLKCTRL register can be configured only when the I2C is disabled (I2CEN=0).