F767 USB DFU - upload firmware

[HMSEdinburge]

Hello... i am design a board based on STM32F767 using USB to upload and upgrade firmware i.e. USB DFU could anyone advise any EVK or schematic daigram for USB to STM32F767 ? Pls advise soon. 

[FBL]

Hi @HMSEdinburge 

You can find schematics under cad resources, schematics pack for Nucleo F767ZI.

[HMSEdinburge]

Hello.. Anyone can advise if using USB Device for DFU, which crystal should i use? 25MHz? Why i dun see the 25 MHz crystal on 767 Nucleo ? 

if i only include the 8 MHz crystal is it fine to drive the USB Device DFU? Please advise? 

[Tesla DeLorean]

Doesn't AN2606 state the accepted crystal frequencies?? Pretty sure 8 or 25 MHz meet requirements..

[FBL]

Hi @HMSEdinburge 

Indeed it should be ok, here is an example provided using the same board in device mode, 

Regarding your second question, when using an 8 MHz HSE, it is mentioned in the datasheet that the USB OTG controller requires a dedicated 48 MHz clock, which is generated by a PLL connected to the HSE oscillator. There is no restriction on the source, as the PLL multipliers can achieve a 48 MHz clock source to feed the USB peripheral.

If your questions are answered, click on Accept as Solution.