Datasheet

STM32F051x Functional overview
Doc ID 018746 Rev 2 19/22
3.15 Serial peripheral interface (SPI)/Inter-integrated sound
interfaces (I
2
S)
Up to two SPIs are able to communicate up to 18 Mbits/s in slave and master modes in full-
duplex and simplex 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 simplex communication mode. It can be configured to
transfer 16 and 24 or 32 bits with16-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 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.
Refer to Ta bl e 7 for the differences between SPI1 and SPI2.
Table 6. STM32F051xx USART implementation
USART modes/features
(1)
1. X = supported.
USART1 USART2
Hardware flow control for modem X X
Continuous communication using DMA X X
Multiprocessor communication X X
Synchronous mode X X
Smartcard mode X
Single-wire half-duplex communication X X
IrDA SIR ENDEC block X
LIN mode X
Dual clock domain and wakeup from Stop mode X
Receiver timeout interrupt X
Modbus communication X
Auto baud rate detection X
Driver Enable X X
Table 7. STM32F051x SPI/I2S implementation
SPI features
(1)
1. X = supported.
SPI1 SPI2
Hardware CRC calculation X X
Rx/Tx FIFO X X
NSS pulse mode X X
I2S mode X
TI mode X X