STM32L496VG on JTAG surfboard

[HXE]

Hi Everybody,

I have a number of Stm32L496VG without crystals but, with pin headers from 3 years ago that I would like to design a new (something) with.

These were designed while then learning the stm32 MCUs as I was moving away from PIC MCUs. Bottom line I, decided during that time to develop my own. 

My question is, since I have the option to run these boards without an external crystal, in this new design I'm generating,

I will use an 8mhz crystal but, as close as possible to the MCU. 

What should I be aware of meaning MCU, Pin header, and Crystal? 

Below, the MCU and its traces are to be removed. The capacitors and crystal as well, is to be moved closer to the pins as possible. Looking at the Photo, I'm thinking it may be a better idea to moved them opposite side of the headers since the MCU will be topside on its PCB.

Will the crystal work this way?

Picture below show's the PCB that is used to program 

the MCU. Of course, it had to be soldered.

[TDK]

The crystal should be next to the chip with short traces in order for HSE to work best. Will it work if you don't do everything as recommended? Usually, but there aren't any guarantees here. Moving it an inch away from the STM32 doesn't seem promising. Breaking out the HSE_IN/OUT pins to headers in addition to crystals will lower your chances. Take a look at the Nucleo schematic and layout to see what can be done with solder bridges if the crystal is optional.

Guidelines for oscillator design on STM8AF/AL/S and STM32 MCUs/MPUs - Application note

[HXE]

TDK,

Thanks for this bit of information. It's greatly appreciated! For validating the overall design, the good thing is, we're only having a few boards made. The purpose of the board design doesn't require such high timing accuracy so, in the event that it doesn't work, we can do with out the external clock in this setup.

Thanks for your time and information. I'll provide the details once we reach this road.

HXE