DMA Request Synchronization?

[sreyas40]

What does DMA Request synchronization do? In the case of SPI_Rx does it trigger SPI reception when TIM12 updates (overflow) if i set synchronization signal to be TIM12 TRGO

[TDK]

Yes. The Reference Manual, which is your best source for understanding how the chip works, goes over it in some detail. The DMA request is held until a sync event happens, in this case TIM12_TRGO, which is the timer update if TRGO is set to the update event.