ADS7142: ADC converting autonomous operation

Hello,

When the device is in Autonomous mode, conversion results are not available.

You will need to exit Autonomous mode to be able to output conversion results, this overrules the settings for autonomous mode, meaning you do not need to worry about setting any of the alert settings. This would mean that you are now operating in manual or auto sequence.

If you are trying to read the FIFO, this is different. the Data Buffer operation is further explained in page 23 and on of the datasheet

You will need to set the SEQ_ABORT bit to be able to read the FIFO, if you do not wait until the trigger. the FIFO would need to be set as Pre-Alert, this way the FIFO begins to store data, even without the trigger.

To read data, you just need to read from the device, without a register address. if the Accumulator is enabled, then that data will reflect this, if not, then the 12 bit data will be provided

Note, that once the SEQ_START bit is set, which will need to be done to return to Autonomously monitoring, the FIFO will be reset.

Regards

Cynthia

Hi Cynthia;

Thank you for the quick response.

The data buffer read is confusing to me.  I plan on using both channels.  So how does this work for reading the two channels?  Do you get sample 1 from channel 0 then sample 1 from channel 1 or do you get 16 samples from channel 0 and then 16 samples from channel 1?  

How does the device differentiate between a buffer read and the register read?  It appears the only difference is that the register read is preceded by a write of the command and register address.   Is there a command to put it into a buffer read mode or does this happen automatically after a completed transaction?