SBAS824 October 2018 ADS1235
PRODUCTION DATA.
In continuous-conversion mode, DRDY is driven high when conversions are started and is driven low when conversion data are ready. During data readback, DRDY returns high at the end of the read operation. If the conversion data are not read, DRDY pulses high 16 fCLK cycles prior to the next falling edge.
To read conversion data before the next conversion is ready, send the complete read-data command 16 fCLK cycles before the next DRDY falling edge. If the readback command is sent less than 16 fCLK cycles before the DRDY falling edge, either old or new conversion data are provided, depending on the timing of when the command is sent. In the case that old conversion data are provided, DRDY driven low is delayed until after the read data operation is completed. In this case, the DRDY bit of the STATUS byte is cleared to indicate the same data have been read. If new conversion data are provided, DRDY transitions low at the normal period of the data rate. In this case, the DRDY bit of the STATUS byte is set to indicate that new data have been read. To make sure new data are read back, wait until DRDY asserts low before starting the data read operation.