OLIMEX© 2015
STM32-P405 user's manual
6.7 RS232_2 connector
The STM32F405xx embeds four universal synchronous/asynchronous receiver transmitters (USART1,
USART2, USART3 and USART6) and two universal asynchronous receiver transmitters (UART4 and
UART5). The RS232_2 connector gives access to USART2 with throughput of 5.25 Mbit/s.
By default RTS and CTS signals are disconnected. You can enable them by closing the jumpers RTS_E
and CTS_E.
The circuit for the serial connection includes the ST3232 IC – it adjusts the external levels of USART to
suitable levels.
RS232_2 connector
Pin #
Signal name
1
Not connected
2
USART2_TX
3
USART2_RX
4
Not connected
5
GND
6
Not connected
7
UART2_RTS
8
WAKE-UP (CTS)
9
NC
6.8 SD/MMC card connector
SD/MMC slot is an SD card slot connector, located on the bottom of STM32-P405. It works with the
“large” SD and MMC cards.
SD/MMC card connector
Pin # Connector signal name
Wire name
Microcontroller pin #
1
CD/DAT3/CS
SPI2_NSS
33
2
CMD/DI
SPI2_MOSI
36
3
VSS1
VSS (GND)
Any GND
4
VDD
SD_VCC1
Any 3.3V pin
5
CLK/SCLK
SPI2_SCK
34
6
VSS2
VSS (GND)
Any GND
7
DAT0/DO
SPI2_MISO
35
8
DAT1/RES
Pulled-up (held at logical 1)
Not connected
9
DAT2/RES
Pulled-up (held at logical 1)
Not connected
Additionally, there are the WP (write protect) and CP (card presence) switches that are responsible,
respectively, for sensing whether the card is locked for reading, and whether there is a card inserted.
You can manipulate the availability of WP and CP by manipulating WP_E and CP_E jumpers.
Disconnecting these jumpers would disable the WP and CP wires from the connector.
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