very fast SPI

Technical discussions around xCORE processors (e.g. xcore-200 & xcore.ai).
stefanharjes
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Joined: Wed Jun 01, 2011 7:33 pm

very fast SPI

Post by stefanharjes »

Hi all,

I am looking for a microprocessor which is able to run very fast SPI master mode
(100MHz SCLK, 18bits transfer), in order to interface a LTC2379 ADC. Does anybody know
if one of the XMOS processors are capable of such transfer?

Best

Stefan


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Bianco
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Joined: Thu Dec 10, 2009 6:56 pm

Post by Bianco »

You can forget 100 MHz, the maximum toggle speed is around 60 MHz.
Are you intending to daisy chain multiple ADC's? Otherwise you don't need such a fast clock.
stefanharjes
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Posts: 13
Joined: Wed Jun 01, 2011 7:33 pm

Post by stefanharjes »

yes I have read about the toggle frequency of 60MHz, but I thought this assumes an external clock source. With SPI master mode the clock is generated by the XS1 and so I thought this maximum does not apply.

In the XS1-L clock frequency control guide I read that you can adjust the reference clock to any frequency up to the system clock, which can be 400MHz. And then it says, that the ports can be run at half that frequency (example is 133MHz reference clock and 66MHz port configuration).

Best

Stefan
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Bianco
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Joined: Thu Dec 10, 2009 6:56 pm

Post by Bianco »

I could be wrong about it, don't take my word for granted.