Functional overview
STM32F042x4 STM32F042x6
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DocID025832 Rev 5
3.16
Serial peripheral interface (SPI) / Inter-integrated sound
interface (I
2
S)
Up to two SPIs are able to communicate up to 18 Mbit/s in slave and master modes in full-
duplex and half-duplex communication modes. The 3-bit prescaler gives 8 master mode
frequencies and the frame size is configurable from 4 bits to 16 bits.
One standard I
2
S interface (multiplexed with SPI1) supporting four different audio standards
can operate as master or slave at half-duplex communication mode. It can be configured to
transfer 16 and 24 or 32 bits with 16-bit or 32-bit data resolution and synchronized by a
specific signal. Audio sampling frequency from 8 kHz up to 192 kHz can be set by an 8-bit
programmable linear prescaler. When operating in master mode, it can output a clock for an
external audio component at 256 times the sampling frequency.
3.17 High-definition
multimedia interface (HDMI) - consumer
electronics control (CEC)
The device embeds a HDMI-CEC controller that provides hardware support for the
Consumer Electronics Control (CEC) protocol (Supplement 1 to the HDMI standard).
This protocol provides high-level control functions between all audiovisual products in an
environment. It is specified to operate at low speeds with minimum processing and memory
overhead. It has a clock domain independent from the CPU clock, allowing the HDMI_CEC
controller to wakeup the MCU from Stop mode on data reception.
3.18
Controller area network (CAN)
The CAN is compliant with specifications 2.0A and B (active) with a bit rate up to 1 Mbit/s. It
can receive and transmit standard frames with 11-bit identifiers as well as extended frames
Modbus communication
X
-
Auto baud rate detection
X
-
Driver Enable
X
X
1. X = supported.
Table 10. STM32F042x4/x6 USART implementation (continued)
USART modes/features
(1)
USART1
USART2
Table 11. STM32F042x4/x6 SPI/I
2
S implementation
SPI features
(1)
1. X = supported.
SPI1
SPI2
Hardware CRC calculation
X
X
Rx/Tx FIFO
X
X
NSS pulse mode
X
X
I
2
S mode
X
-
TI mode
X
X
