About the functions of connectors

tatsuya · ‎2022-11-13

Hi,team

Currently, I'm designing a PCB with "STM32MP151AAD3T".

I'm designing our own PCB with reference to "STM32MP157x-EV1".

When developing software using this EVM, the connection to PC shown in the attached figure is recommended as following URL.

(https://wiki.st.com/stm32mpu/wiki/Getting_started/STM32MP1_boards/STM32MP157x-EV1/Let%27s_start/Unpack_the_STM32MP157x-EV1_board)

I have questions about the connection with two connectors as follows.

Q1. About "ST-LINK/V2-1 Connector"

Is it correct to consider that connecting this USB connector to a PC is equivalent to connecting via ST-LINK?

For the PCB I'm designing, I want to use a JTAG connector to connect ST-LINK instead of the USB connector.

Q2. About "USB OTG Connector"

What can I do by connecting the USB OTG connector to a PC?

Best regards,

PatrickF · ‎2022-11-16

Hi,

There is no difference, with STM32MP, CubeProgrammer always use USB OTG High-Speed to flash the board whatever SD-Card, Serial-NOR, Serial-NAND, NAND, eMMC (or a combination of those).

Only the flashlayout file (TSV) is different. https://wiki.st.com/stm32mpu/wiki/STM32CubeProgrammer_flashlayout#Article_purpose

Before developing your own board, I recommend to get insight the existing boards (EV1 or DK2) and read AN5031.

Unlike STM32 MCUs, changes Vs the STM32 MPUs default deliveries has to be carefully done (only if mandatory for your product) in order to avoid additional integration effort or pitfalls.

Usually starting by prototyping using existing ST board (EV1 or DK2) or existing 3rd party SOM is a good idea to avoid jeopardize the efforts.

Regards.

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PatrickF · ‎2022-11-14

Hi @tatsuya

A1: STLINK USB is to connect the embedded ST-LINKV2 to both JTAG/SWD and UART Virtual Com Port (VCP). VCP is usually used for system Console. You are right, on your board, you should provide a JTAG connector (See AN5031 for an example using STDC14 connector which provide direct connection to an ST-LINKV3 including VCP).

A2: OTG connector is required as USB connection to STM32CubeProgrammer as flashing is done using USB (and not STLINK unlike STM32 MCUs). On your platform, you could also use basic USB Type-C device. Note that Using USB port #2 is mandatory as only this one is connected to internal OTG IP. See AN5031 for example.

If you are not confident on your design choices, we recommend to stick as you can to an existing development board example (e.g. STM32MP157F-EV1 or STM32MP157F-DK2) and prune unwanted portions as well as add your own specific circuitry.

Regards.

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tatsuya · ‎2022-11-15

Hi PatrickF-san

Thank you for your reply.

> A2: OTG connector is required as USB connection to STM32CubeProgrammer as flashing is done using USB (and not STLINK unlike STM32 MCUs).

In this environment, I think the SD card is flashed.

In case flashing eMMC via STM32CubeProgrammer, is this OTG also available?

Best regards,

PatrickF · ‎2022-11-16

Hi,

There is no difference, with STM32MP, CubeProgrammer always use USB OTG High-Speed to flash the board whatever SD-Card, Serial-NOR, Serial-NAND, NAND, eMMC (or a combination of those).

Only the flashlayout file (TSV) is different. https://wiki.st.com/stm32mpu/wiki/STM32CubeProgrammer_flashlayout#Article_purpose

Before developing your own board, I recommend to get insight the existing boards (EV1 or DK2) and read AN5031.

Unlike STM32 MCUs, changes Vs the STM32 MPUs default deliveries has to be carefully done (only if mandatory for your product) in order to avoid additional integration effort or pitfalls.

Usually starting by prototyping using existing ST board (EV1 or DK2) or existing 3rd party SOM is a good idea to avoid jeopardize the efforts.

Regards.

In order to give better visibility on the answered topics, please click on 'Select as Best' on the reply which solved your issue or answered your question. See also 'Best Answers'

In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.