Datasheet

AD7176-2 Data Sheet
Rev. A | Page 34 of 68
OPERATING MODES
CONTINUOUS CONVERSION MODE
Continuous conversion is the default power-up mode. The
AD7176-2 converts continuously, and the
RDY
bit in the status
register goes low each time a conversion is complete. If
CS
is low,
the DOUT/
RDY
line also goes low when a conversion is complete.
To read a conversion, the user writes to the communications
register, indicating that the next operation is a read of the data
register. When the data-word has been read from the data register,
DOUT/
RDY
goes high. The user can read this register additional
times, if required. However, the user must ensure that the data
register is not being accessed at the completion of the next con-
version; otherwise the new conversion word will be lost.
When several channels are enabled, the ADC automatically
sequences through the enabled channels, performing one
conversion on each channel. When all channels have been
converted, the sequence starts again with the first channel. The
channels are converted in order from lowest enabled channel to
highest enabled channel. The data register is updated as soon as
each conversion is available. The DOUT/
RDY
pin pulses low
each time a conversion is available. The user can then read the
conversion while the ADC converts the next enabled channel.
If the DATA_STAT bit in the interface mode register is set to 1,
the contents of the status register, along with the conversion data,
are output each time the data register is read. The status register
indicates the channel to which the conversion corresponds.
Figure 47. Continuous Conversion Mode
DIN
SCLK
DOUT/RDY
CS
0x44 0x44
DATA DATA
11037-071