AMC7812B: AMC7812 SPI communication

Ahamd Moghaddam

Part Number: AMC7812B
Other Parts Discussed in Thread: AMC7812

I am trying to communicate with the AMC7812 through SPI controller and trying to read device ID. I am not able to get device ID.

question: the way I send 24 bit serial command is to divide serial bits to 3 BYTES (3*8 bits) and send each BYTE serially . Chip Select line in SPI bus goes high between consecutive serialized 8 bit chunks. Is it Ok to do so? or a CS line needs to be held asserted (LOW) for 24 clock cycles with no intermittent break?

Cheers

over 2 years ago

0 Akhilesh K over 2 years ago

TI__Mastermind 18546 points

Hi,

You can send data as 3 Bytes, But make sure that exactly 24 falling clock edges must be applied before CS is brought high. If CS is brought high before the 24th falling SCLK edge, or if more than 24 falling SCLK edges are applied before CS is brought high, then the input data are incorrect.

Hope this clarifies your query.

Regards,

0 Ahamd Moghaddam over 2 years ago in reply to Akhilesh K

Prodigy 30 points

Thanks Akhilesh,

as I mentioned I send 8 bits while CSN is asserted LOW and apply 8 clocks . then I dessert CSN to HIGH for a while and then I send another 8 bit data while CSN is asserted LOW and apply 8 clocks and again I deassert CSN to HIGH for a while and I do the same for the third time. so there are 24 falling edges while CSN is held LOW but as I mentioned there is a break between each 8 clock cycles. is it still Ok?