Information

Description STM32F405xx, STM32F407xx
34/185 DocID022152 Rev 4
2.2.24 Serial peripheral interface (SPI)
The STM32F40x feature up to three SPIs in slave and master modes in full-duplex and
simplex communication modes. SPI1 can communicate at up to 42 Mbits/s, SPI2 and SPI3
can communicate at up to 21 Mbit/s. The 3-bit prescaler gives 8 master mode frequencies
and the frame is configurable to 8 bits or 16 bits. The hardware CRC generation/verification
supports basic SD Card/MMC modes. All SPIs can be served by the DMA controller.
The SPI interface can be configured to operate in TI mode for communications in master
mode and slave mode.
2.2.25 Inter-integrated sound (I
2
S)
Two standard I
2
S interfaces (multiplexed with SPI2 and SPI3) are available. They can be
operated in master or slave mode, in full duplex and half-duplex communication modes, and
can be configured to operate with a 16-/32-bit resolution as an input or output channel.
Audio sampling frequencies from 8 kHz up to 192 kHz are supported. When either or both of
the I
2
S interfaces is/are configured in master mode, the master clock can be output to the
external DAC/CODEC at 256 times the sampling frequency.
All I
2
Sx can be served by the DMA controller.
2.2.26 Audio PLL (PLLI2S)
The devices feature an additional dedicated PLL for audio I
2
S application. It allows to
achieve error-free I
2
S sampling clock accuracy without compromising on the CPU
performance, while using USB peripherals.
Table 5. USART feature comparison
USART
name
Standard
features
Modem
(RTS/
CTS)
LIN
SPI
master
irDA
Smartcard
(ISO 7816)
Max. baud rate
in Mbit/s
(oversampling
by 16)
Max. baud rate
in Mbit/s
(oversampling
by 8)
APB
mapping
USART1 X X X X X X 5.25 10.5
APB2
(max.
84 MHz)
USART2 X X X X X X 2.62 5.25
APB1
(max.
42 MHz)
USART3 X X X X X X 2.62 5.25
APB1
(max.
42 MHz)
UART4 X - X - X - 2.62 5.25
APB1
(max.
42 MHz)
UART5 X - X - X - 2.62 5.25
APB1
(max.
42 MHz)
USART6 X X X X X X 5.25 10.5
APB2
(max.
84 MHz)