Simon Kagstrom wrote: > (Email overload!) Busy morning indeed ;-)
> This is already done in the interrupt handler for the data registers. The > filter reset is "far" away from the data registers, so that one is read > separately. With DMA, retrieving some unused registers should be cheap. The amount of data is trivial anyway, and SPI+DMA can then run in parallel to the CPU. > The issue I see with this is that the interrupt would contine to be > asserted until we have actually read the data values, and I don't see > how to handle this in a good way without visiting the interrupt handler > in a loop. I guess looping back to the handler should be okay in this case. This should be a rare race condition anyway. (At 10MHz, DMA should be done reading the 20*8 = 160 bits of STATUS_REG (0x27) through CLICK_SRC (0x39) in about 16us. A completion interrupt handler might even consume more time than that. > Anyway, perhaps a stupid question, but assuming we use some threshold > configuration, is the accelerometer stuff really that much of a > performance problem? That's of course an excellent question :-) - Werner
