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ARM to AD7768

Question asked by chengjinjing on Jul 19, 2016
Latest reply on Nov 23, 2017 by NiallM

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Dear Sir

I have some problems about using AD7768. I use an ARM device to configure AD7768(SPI0 port) and receive DOUT data of AD7668(SPI1 port).I can use SPI0 PORT to configure AD7768 ,but I can’t receive DOUT data of AD7668 through SPI1 port.

For my ARM device .I set the SPI1 port as slave mode, The relative signals are CS, SCLK , MOSI, MISO. For AD7768, all channels data are out to DOUT0, The relative signals are RDY, DCLK , DOUT0. Connecting SCLK to DCLK , MISO to DOUT0 .but I don’t know how to connect  CS of ARM device to AD7768? The slave SPI1 work as blow: if CS is low , the rising edge of clock can trigger the SPI, if number of the rising edge of clock is enough, it will enter in an interrupt.

In figure 1,D0 is DOUT0 of AD7768, D1 is RDY of AD7768, D2 is DCLK of AD7768,

  1. 1) If Connecting CS to GND; CS is always low, DCLK is always working, The arm device will enter interrupt frequently, which will cause consuming resources of arm device. and the arm device will receive many invalid data in t2(figure 1) time.
  2. 2) If Connecting CS to RDY; CS is low in most time, DCLK is always working, The arm device will also enter interrupt frequently, which will also cause consuming resources of arm device. and the arm device will also receive many invalid data in t2(figure 1) time.

How to use arm device to receive AD7768 DOUT data?

Thank you;

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