Datasheet

Data Sheet AD7324
Rev. B | Page 25 of 36
SEQUENCER OPERATION
DIN: WRITE TO RANGE REGISTER TO SELECT THE RANGE
FOR EACH ANALOG INPUT CHANNEL.
DOUT: CONVERSION RESULT FROM CHANNEL 0, ±10V
RANGE, SINGLE-ENDED MODE.
CS
DIN: TIE DIN LOW/WRITE BIT = 0TO CONTINUE TO CONVERT
THROUGH THE SEQUENCE OF CHANNELS.
DOU
T: CONVERSION RESULT FROM FIRST CHANNEL IN
THE SEQUENCE.
CS
DIN: WRITE TO SEQUENCE REGISTER TO SELECT THE
NEW SEQUENCE.
DOUT: CONVERSION RESULT FROM CHANNEL X IN
THE FIRST SEQUENCE.
CS
DIN: WRITE
TO CONTROL REGISTER TO START THE
SEQUENCE, Seq1 = 0, Seq2 = 1.
DOUT: CONVERSION RESULT FROM CHANNEL 0,
SINGLE-ENDED MODE, RANGE SELECTED IN
RANGE REGISTER.
CS
DIN: WRITE TO SEQUENCE REGISTER TO SELECT THE
ANALOG INPUT CHANNELS TO BE INCLUDED IN
THE SEQUENCE.
DOUT: CONVERSION RESULT FROM CHANNEL 0,
SINGLE-ENDED MODE, RANGE SELECTED IN
RANGE REGISTER.
CS
POWER ON.
CONTINUOUSLY CONVERT
ON THE SELECTED SEQUENCE
OF CHANNELS.
DIN TIED LOW/WRITE BIT = 0.
SELECTING A NEW SEQUENCE.
DIN: WRITE TO CONTROL
REGISTER TO STOP THE
SEQUENCE, Seq1 = 0, Seq2 = 0.
DOUT: CONVERSION RESULT
FROM CHANNEL IN SEQUENCE.
CS
S
TOPPING
A SEQUENCE.
04864-031
Figure 44. Programmable Sequence Flowchart
The AD7324 can be configured to automatically cycle through
a number of selected channels using the on-chip sequence
register with the Seq1 bit and the Seq2 bit in the control register.
Figure 44 shows how to program the AD7324 register to operate in
sequence mode.
After power-up, all of the three on-chip registers contain default
values. Each analog input has a default input range of ±10 V. If
different analog input ranges are required, a write to the range
register is required. This is shown in the first serial transfer of
Figure 44.
This initial serial transfer is only necessary if input ranges other
than the default ranges are required. After the analog input ranges
are configured, a write to the sequence register is necessary to
select the channels to be included in the sequence. Once the
channels for the sequence have been selected, the sequence can
be initiated by writing to the control register and setting Seq1 to
0 and Seq2 to 1. The AD7324 continues to convert the selected
sequence without interruption provided that the sequence register
remains unchanged, and Seq1 = 0 and Seq2 = 1 in the control
register.