The STM32F746G-DISCO discovery board (32F746GDISCOVERY) is a complete demonstration and development platform for STMicroelectronics ARM® Cortex®-M7 corebased STM32F746NGH6 microcontroller. This microcontroller features four I2Cs, six SPIs with three multiplexed simplex I2S, SDMMC, four USARTs, four UARTs, two CANs, three 12-bit ADCs, two 12-bit DACs, two SAIs, 8- to 14-bit digital camera module interface, internal 320+16+4-Kbyte SRAM and 1-Mbyte Flash memory, USB HS OTG, USB FS OTG, Ethernet MAC, FMC interface, Quad-SPI interface, SWD debugging support. This discovery board offers everything required for users to get started quickly and develop applications easily.
The full range of hardware features on the board helps users to evaluate almost all peripherals (USB OTG HS, USB OTG FS, 10/100-Mbit Ethernet, microSD™ card, USART, SAI Audio DAC stereo with audio jack input and output, MEMS digital microphones, SDRAM, Quad-SPI Flash memory, 4.3-inch color LCD-TFT with a capacitive multi-touch panel, SPDIF RCA input, etc.) and to develop their applications. Arduino™ Uno V3 connectors make it possible to easily connect extension shields or a daughterboard for users’ specific applications. The integrated ST-LINK/V2-1 provides an embedded in-circuit debugger and programmer for the STM32.
The STM32F746G-DISCO board comes with the STM32 comprehensive software HAL library together with various packaged software examples, as well as a direct access to ARM® mbed™ online resources at http://mbed.org.
340 Kbytes of RAM, in BGA216 package
Supported by a wide choice of integrated development environments
The ST-LINK/V2-1 programming and debugging tool is integrated on the
STM32F746G-DISCO discovery board. Compared to ST-LINK/V2 the changes are listed below.
The new features supported on ST-LINK/V2-1 are:
These features are no more supported on ST-LINK/V2-1:
For all general information concerning debugging and programming features common between V2 and V2-1 refer to ST-LINK/V2 in-circuit debugger/programmer for STM8 and STM32 User manual (UM1075).
The STM32F746G-DISCO discovery board is designed to be powered by 5V DC power supply. It is possible to configure the discovery board to use any of the following five sources for the power supply:
ST-LINK/V2-1 (USB 5V power source on silkscreen of JP1 (5V link)). It is the default setting. If the USB enumeration succeeds (as explained below), the ST-LINK 5V link power is enabled, by asserting the PWR_ENn signal. This pin is connected to a power switch (ST890), which powers the board. This power switch features also a current limitation to protect the PC in case of a short-circuit on the board (more than 600 mA).
The STM32F746G-DISCO discovery board can be powered from the ST-LINK USB connector CN14 (5V link), but only the ST-LINK circuit has the power before USB enumeration, because the host PC only provides 100 mA to the board at that time. During the USB enumeration, the STM32F746G-DISCO board asks for the 500 mA power to the host PC. If the host is able to provide the required power, the enumeration ends by a “SetConfiguration” command and then, the power transistor U8 (ST890) is switched ON, the red LED LD2 is turned ON, thus the STM32F746G-DISCO board can consume no more than 500 mA of current. If the host is not able to provide the requested current, the enumeration fails. Therefore the ST890 (U8) remains OFF and the STM32 part including the extension board will not be powered. As a consequence the red LED LD2 remains turned OFF. In this case it is mandatory to use an external power supply.
It is mandatory to power the board first using JP1 (5V ext) or (usb_hs) or (usb_fs), then connecting the USB cable to the PC. Proceeding this way ensures that the enumeration succeeds thanks to the external power source.
The following power sequence procedure must be respected:
If this order is not respected, the board may be powered by VBUS first from ST-LINK, and the following risks may be encountered:
Up to 3 clock sources as described below:
The reset signal of STM32F746G-DISCO discovery board is active low and the reset sources include:
An audio codec WM8994ECS/R from CIRRUS with 4 DACs and 2ADCs is connected to SAI interface of STM32F746NGH6. It communicates with STM32F746NGH6 via I2C bus shared with the camera module and I2C extension connector.
The STM32F746G-DISCO discovery board supports USB OTG full speed communication via a USB micro-AB connector (CN13) and USB power switch (U6) connected to VBUS. The discovery board can be powered by this USB connection at 5V DC with 500mA current limitation.
A green LED LD5 will be lit in one of these cases:
The red LED LD6 will be lit when an overcurrent occurs.
Note: STM32F746G-DISCO board should be powered by an external power supply when using OTG function.
The STM32F746G-DISCO discovery board supports the USB OTG high speed communication via a USB micro-AB connector (CN12), USB high speed PHY (U15) USB3320C-EZK from MICROCHIP for high speed function.
The discovery board can be powered by the USB connectors (CN12) at 5V DC with 500mA current limitation.
A USB power switch (U7) is also connected on VBUS and provides power to CN12.
The green LED LD4 will be lit in one of these cases:
• Power switch (U17) is ON and STM32F746G-DISCO works as an USB host • VBUS is powered by another USB host when STM32F746G-DISCO works as an USB device.
The red LED LD3 will be lit when an overcurrent occurs.
Note: STM32F746G-DISCO board should be powered by an external power supply when using OTG function.
The 2-Gbyte (or more) microSD card connected to the SDMMC1 port of the STM32F746NGH6 is supported by the board.
The STM32F746G-DISCO discovery board supports 10/100-Mbit Ethernet communication by a PHY LAN8742A-CZ-TR (U9) from MICROCHIP and RJ45 jack (CN9). Ethernet PHY is connected to STM32F746NGH6 via RMII interface.
25 MHz clock for the PHY is generated by the oscillator X2, the 50 MHz clock for the STM32F746NGH6 is generated by the PHY RMII_REF_CLK.
128-Mbit SDRAM (MT48LC4M32B2B5-6A from MICRON) is connected to the FMC interface of the STM32F746NGH6. Only the lowest 16-bit data are used (64-Mbit accessible). DQ16 to DQ31 are unused and connected to a 10K ohm pull-down resistor.
128-Mbit Quad-SPI Nor Flash memory (N25Q128A13EF840E from MICRON) is connected to the Quad-SPI interface of the STM32F746NGH6.
A connector P1 with the DCMI signals is available to connect a camera module such as STM32F4DIS-CAM (ST order code).
The color display from ROCKTECH, 4.3-inch 480x272 LCD-TFT with capacitive touch panel is connected to RGB LCD interface of the STM32F746NGH6.