Enhancement: Switch U8 (F411) clock source to U1 (F103) MCO

[set5una]

Thanks for releasing this design.

The board currently has two crystal oscillators: X1 for the STM32F103 and X2 for the STM32F411. Because the F103 exposes a fully configurable Microcontroller Clock Output MCO on PA8, the second oscillator X2 is unnecessary and redundant.

Proposal: remove oscillator X2 and route PA8 (MCO) from the STM32F103 directly to the STM32F411 OSC_IN pin.

The F103 can drive the F411 with any of these sources via MCO: HSI, HSE, PLLCLK/2, or SYSCLK, which provides more flexible clocking for the F411.

Please refer to STM32F1 RM0008 pp 7.2.10 for information on MCO.

[messi6199]

Mco can do so many things,i just found out.Thanks.