RE: saadc scan mode timing

haakonsh — Mon, 04 Feb 2019 09:57:50 GMT

"What is extra time it takes for the easyDMA to store the samples in RAM ? In other words what is the time between nrfx_saadc_sample() (or ppi trigger) to SAADC_END event ?"

- That is dependent on the availablility of the EasyDMA slave. If another EasyDMA master(another peripheral, like a serial interface) is accessing the EasyDMA slave the SAADCs EasyDMA master must wait until the given slave is available. You can circumvent this scenario by making sure that only the SAADC is using the given slave by reserving the address space of that EasyDMA slave. See https://www.nordicsemi.com/DocLib/Content/Product_Spec/nRF52840/latest/memory?17#ram for details.

"The statement just below the gray frame is "A DONE event signals that one sample has been taken"

Is it "one sample" or should it be "one sample per enabled channel" ?"

- I agree that it is a bit misleading. I believe one 'sample' in this context refers to one sample of each enabled channel.