Name State Priority Stack Num
---------------------------------------------
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B : Blocked, R : Ready, D : Deleted, S : Suspended
Introduction
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.
Features
-
STM32F746NGH6 microcontroller featuring 1 Mbyte of Flash memory and
340 Kbytes of RAM, in BGA216 package
- On-board ST-LINK/V2-1 supporting USB reenumeration capability
- ARM® mbed™-enabled (see http://mbed.org)
- USB functions: virtual COM port, mass storage, debug port
- 4.3-inch 480x272 color LCD-TFT with capacitive touch screen
- Camera connector
- SAI audio codec
- Audio line in and line out jack
- Stereo speaker outputs
- Two ST MEMS microphones
- SPDIF RCA input connector
- Two push buttons (user and reset)
- 128-Mbit Quad-SPI Flash memory
- 128-Mbit SDRAM (64-Mbit accessible)
- Connector for microSD card
- RF-EEPROM daughterboard connector
- USB OTG HS with Micro-AB connectors
- USB OTG FS with Micro-AB connectors
- Ethernet connector compliant with IEEE-802.3-2002
-
Five power supply options:
- ST LINK/V2-1
- USB FS connector
- USB HS connector
- VIN from Arduino connector
- External 5 V from connector
- Power supply output for external applications: 3.3 V or 5 V
- Arduino Uno V3 connectors
- Comprehensive free software including a variety of examples, part of STM32Cube package
Supported by a wide choice of integrated development environments
Embedded ST-LINK/V2-1
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:
- USB software reenumeration
- Virtual Com port interface on USB
- Mass storage interface on USB
-
USB power management request for more than 100 mA power on USB
These features are no more supported on ST-LINK/V2-1:
- SWIM interface
- Application voltage lower than 3 V
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).
Power supply
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:
- 5V DC power adapter connected to JP2 (external power supply on silkscreen of JP1 (5V ext)). In this case, the STM32F746G-DISCO discovery board must be powered by a power supply unit or by an auxiliary equipment complying with the standard EN-60950-1: 2006+A11/2009, and must be Safety Extra Low Voltage (SELV) with limited power capability.
- 7-12V DC power from CN6 pin named Vin on silkscreen, the extension connectors for Arduino UNO shields or daughterboard (external power source on silkscreen of JP1 (5V ext)).
-
5V DC power with limitation from CN14, the USB type mini-B connector of
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.
Programming/debugging when the power supply is not from
ST-LINK (5V link)
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:
- Connect the jumper JP1 on (5V ext) or (usb_hs) or (usb_fs)
- Connect the external power source to JP2 or CN6 or CN12 or CN13
- Check the red LED LD2 is turned ON
-
Connect the PC to USB connector CN14
If this order is not respected, the board may be powered by VBUS first from ST-LINK, and the following risks may be encountered:
- If more than 500 mA current is needed by the board, the PC may be damaged or current can be limited by the PC. As a consequence the board is not powered correctly.
- 500 mA will be requested at the enumeration, so there is a risk that the request is rejected and enumeration does not succeed if the PC cannot provide such current.
Clock sources
Up to 3 clock sources as described below:
- X1, 24 MHz oscillator for the USB OTG HS PHY and camera module (daughterboard)
- X2, 25 MHz oscillator for the STM32F746NGH6 microcontroller and Ethernet PHY
- X3, 32 KHz crystal for the STM32F746NGH6 embedded RTC
Reset sources
The reset signal of STM32F746G-DISCO discovery board is active low and the reset sources include:
- Reset button B2
- Arduino Uno shield board from CN6
- Embedded ST-LINK/V2-1
Audio
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 analog line input is connected to ADC of WM8994ECS/R through blue audio jack CN11.
- The analog line output is connected to DAC of WM8994ECS/R via green audio jack CN10.
- Two external speakers can be connected to WM8994ECS/R via JP3 for right speaker and JP4 for left speaker.
- Two digital microphones (ST MEMs microphone) MP34DT01TR are on the STM32F746G-DISCO discovery board. They are connected to the input digital microphones of WM8994ECS/R.
- One coaxial connector CN1 is implemented on STM32F746G-DISCO to receive external audio data compatible with SPDIF specification.
USB OTG FS
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:
- Power switch (U6) 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 LD6 will be lit when an overcurrent occurs.
Note: STM32F746G-DISCO board should be powered by an external power supply when using OTG function.
USB OTG HS
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.
microSD card
The 2-Gbyte (or more) microSD card connected to the SDMMC1 port of the STM32F746NGH6 is supported by the board.
Ethernet
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.
SDRAM memory
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.
Quad-SPI Nor Flash memory
128-Mbit Quad-SPI Nor Flash memory (N25Q128A13EF840E from MICRON) is connected to the Quad-SPI interface of the STM32F746NGH6.
Camera module
A connector P1 with the DCMI signals is available to connect a camera module such as STM32F4DIS-CAM (ST order code).
Display LCD-TFT
The color display from ROCKTECH, 4.3-inch 480x272 LCD-TFT with capacitive touch panel is connected to RGB LCD interface of the STM32F746NGH6.