DocID018909 Rev 11
863/1731
RM0090
Inter-integrated circuit (I
2
C) interface
864
27.6.10 I
2
C FLTR register (I2C_FLTR)
Address offset: 0x24
Reset value: 0x0000
The I2C_FLTR is available on STM32F42xxx and STM32F43xxx only.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
ANOFF
DNF[3:0]
rw
rw
rw
rw
rw
Bits 15:5 Reserved, must be kept at reset value
Bit 4
ANOFF
: Analog noise filter OFF
0: Analog noise filter enable
1: Analog noise filter disable
Note: ANOFF must be configured only when the I2C is disabled (PE = 0).
Bits 3:0
DNF[3:0]
: Digital noise filter
These bits are used to configure the digital noise filter on SDA and SCL inputs. The digital filter
will suppress the spikes with a length of up to DNF[3:0] * TPCLK1.
0000: Digital noise filter disable
0001: Digital noise filter enabled and filtering capability up to 1* TPCLK1.
...
1111: Digital noise filter enabled and filtering capability up to 15* TPCLK1.
Note: DNF[3:0] must be configured only when the I2C is disabled (PE = 0). If the analog filter
is also enabled, the digital filter is added to the analog filter.