Re: AD7714 help


Arlet wrote:
Prakruthi wrote:

If you use a MCU with a SPI peripheral, it could be set to the wrong
SPI mode. Hook up a digital scope or logic analyzer to the SCL,CS#,
DIN,DOUT pins, and compare the diagrams with the data***, make sure
the data gets transferred on the right clock edge. Then try write/read
back again, and look at the interface to see if the correct value is
passed, and then see if this same value makes it all the way to the
application.

Hi,

I did compare the signals with the clock and found out that the data is
not getting transferred on the right clock edge. How do I set the clock
sync right. How do I determine what the right clock frequency for the SPI transfer
would be.

It depends on the SPI master you're using... if it's halfway decent, it
has configuration bits for SPI clock polarity, or SPI mode. Check the
data***. This is something else than the SPI clock frequency, which
may be OK. If you want more help, you'll need to post what device
you're using to talk to the AD7714.

Hi Arlet,

Firstly, thank you for the quick response.

I m using the ATMega8 to communicate with the AD7714. So it has amazing
options for configuring the SPI clock frequency. The ATMega8 runs at a
frequency of 14.567MHz. And im using a SCLK frequency of fclkin/128 to
drive the slave(AD7714), with a CPOL=1 and CHPA=1. I have no idea what
the problem could be , cause I have tried all the different SCLK
frequencies that are available.

Hope this information helps you help me out:)

Regards,
Prakruthi

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