embedded - Microcontroller to interface with Led Driver -


my knowledge of micro-controllers limited @ point, here goes.

i have led driver pt6959 i'm trying interface with. data read serially driver ic on input clk rising edge once stb input line goes low.

my question is, how know input clk frequency should be?

does matter? or should same led driver osc pin frequency?

i've read datasheet can't find reference specifying input clk frequency.

if microcontroller has spi port, connect follows:

din <-- spi-mosi clk <-- spi-clk stb <-- cs (often gpio rather dedicated spi chipselect) 

the spi peripheral of work you. spi peripherals allow different combinations of polarity , phase known modes:

mode  cpol  cpha 0     0     0 1     0     1 2     1     0 3     1     1 

the pt6959 operates in mode 3.

the clock rate not critical. if bit-banging rather using spi, need not periodic or fixed - state of din on rising , falling edges critical - not frequency. device have maximum rate - data sheet specifies in terms of minimum mark/space widths of >=400ns, assuming 50% mark:space, correspond 1.25mhz, there little benefit in operating @ maximum speed.


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