STM32f746vg internal oascillators?

[Anders Persson]

Posted on March 09, 2018 at 11:36

Hi!

I am currently developing a wireless sensor node with the STM32f746vgt6 MCU. As I understand from reading the data sheet it is possible to run the MCU on its internal oscillators instead of adding external crystal oscillators. However when trying to connect to the chip through a JTAG device, I cant get a connection...Therefore I am starting to wondering if I have miss interpreted the data sheet and that it must have external oscillators connected to the chip? I can not think of any other problem right now...Best regardsAnders Persson

[Sirac]

Posted on March 09, 2018 at 13:55

JTAG has it's own clock so you don't need external crystall. So it's an other issue

[Andrew Neil]

Posted on March 09, 2018 at 14:03

You're not putting the CPU into a low-power mode, are you?

And/or disabling the pins used by JTAG?

[Tilen MAJERLE]

Posted on March 09, 2018 at 14:12

Hello

wippp

‌,

please verify:

• SWD (or JTAG) pinout matches your setup
• MCU is not in low-power mode. If it is, useConnect under reset option
• You are not disabling SWD/JTAG pins by software

Best regards,

Tilen

[Anders Persson]

Posted on March 12, 2018 at 10:16

Thank you for your fast response!

I have checked that the JTAG is properly connected and also measured continuity between my connector and the STM32f746vg pins.

Can I physically put the MCU in low power mode? And how do I know that it is in this mode? Either way I have tried to connect under reset without any success...

In the software I have tried to connect with booth JTAG and SWD.

Maybe it is some problem with the drivers for the JTAG device. It is a Mikroelektronika mikroprog programmer which they claim should work with the STM32f746vg MCU.

Best regards

/Anders