Datasheet

DS10690 Rev 6 31/144
STM32L071xx Functional overview
33
3.15 Communication interfaces
3.15.1 I
2
C bus
Up to three I
2
C interfaces (I2C1 and I2C3) can operate in multimaster or slave modes.
Each I
2
C interface can support Standard mode (Sm, up to 100 kbit/s), Fast mode (Fm, up to
400 kbit/s) and Fast Mode Plus (Fm+, up to 1 Mbit/s) with 20 mA output drive on some I/Os.
7-bit and 10-bit addressing modes, multiple 7-bit slave addresses (2 addresses, 1 with
configurable mask) are also supported as well as programmable analog and digital noise
filters.
In addition, I2C1 and I2C3 provide hardware support for SMBus 2.0 and PMBus 1.1: ARP
capability, Host notify protocol, hardware CRC (PEC) generation/verification, timeouts
verifications and ALERT protocol management. I2C1/I2C3 also have a clock domain
independent from the CPU clock, allowing the I2C1/I2C3 to wake up the MCU from Stop
mode on address match.
Each I2C interface can be served by the DMA controller.
Refer to Table 11 for an overview of I2C interface features.
Table 10. Comparison of I2C analog and digital filters
Analog filter Digital filter
Pulse width of
suppressed spikes
≥ 50 ns
Programmable length from 1 to 15
I2C peripheral clocks
Benefits Available in Stop mode
1. Extra filtering capability vs.
standard requirements.
2. Stable length
Drawbacks
Variations depending on
temperature, voltage, process
Wakeup from Stop on address
match is not available when digital
filter is enabled.
Table 11. STM32L071xx I
2
C implementation
I2C features
(1)
1. X = supported.
I2C1 I2C2 I2C3
7-bit addressing mode X X X
10-bit addressing mode X X X
Standard mode (up to 100 kbit/s) X X X
Fast mode (up to 400 kbit/s) X X X
Fast Mode Plus with 20 mA output drive I/Os (up to 1
Mbit/s)
XX
(2)
2. See Table 15: STM32L071xxx pin definition on page 40 for the list of I/Os that feature Fast Mode Plus
capability
X
Independent clock X - X
SMBus X - X
Wakeup from STOP X - X
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.