Datasheet

Data Sheet AD7323
Rev. B | Page 27 of 36
If a change to the range register is required during a sequence, it
is necessary to first stop the sequence by writing to the control
register and setting Seq1 to 0 and Seq2 to 0. Next, the write to
the range register should be completed to change the required
range. The previously selected sequence can be initiated again
by writing to the control register and setting Seq1 to 0 and Seq2
to 1. The ADC converts on the first channel in the sequence.
The AD7323 can be configured to convert a sequence of
consecutive channels (see Figure 45). This sequence begins by
converting on Channel 0 and ends with a final channel as
selected by Bit ADD1 to Bit ADD0 in the control register. In
this configuration, there is no need for a write to the sequence
register. To operate the AD7323 in this mode, set Seq1 to 1 and
Seq2 to 0, and then select the final channel in the sequence by
programming Bit ADD1 to Bit ADD0 in the control register.
Once the control register is configured to operate the AD7323
in this mode, the DIN line can be held low, or the write bit can
be set to 0. To return to traditional multichannel operation, a
write to the control register to set Seq1 to 0 and Seq2 to 0 is
necessar y.
When Seq1 and Seq2 are both set to 0, or when both are set
to 1, the AD7323 is configured to operate in traditional multi-
channel mode, in which a write to Channel Address Bit ADD1
to Bit ADD0 in the control register selects the next channel for
conversion.
DIN: WRITE TO RANGE REGI
STE
R TO SELECT TH
E RANGE
FOR ANALOG IN PUT CHANNELS.
DOUT: C
ON
VE
RSIO
N RES
ULT F
ROM
CHANNEL 0, ±10V
RANGE, SI
NGL
E-ENDE
D M
O
DE.
C
S
DIN: WRITE BIT = 0 OR DIN LIN
E HE
LD L
OW TO
CON
TINU
E
THRO
UGH
SEQUENCE OF C
ONSECU
TIVE
CHANNELS.
DO
UT: CONVERS
ION RESULT
FROM CHANNEL 1
,
RANGE SE
LECTED
IN RANGE REGIS
TER.
CS
DIN: WRITE BIT = 0 OR
DIN
LIN
E HEL
D LOW
TO C
ONT
INUE
T
O CO
NVERT THROUGH THE SEQU
ENCE
OF
CO
NSECU
TIVE CHANNE
LS.
DOUT:
CONVE
RSION RESULT FROM CHANNE
L 0,
RANG
E SEL
ECT
ED IN RANG
E RE
GISTER.
CS
DIN: WR
IT
E T
O
CO
NTR
OL R
EGIS
TER T
O SELECT THE FINAL
CHANNEL IN THE CONSECUTI
VE SE
QU
E
NCE, SE
T Se
q1 =
1
AND
Se
q2 =
0. SE
LECT
OUTPUT CODING FOR SEQUE
NCE.
DOUT: CONVERSIO
N R
ES
ULT F
ROM
CHANNEL
0,
RANG
E SELECTED IN RANGE REGIS
TER
,
SI
NGL
E-ENDED
MODE.
CS
PO
WER
ON.
DIN T
IED LO
W/WRITE BIT
= 0.
CON
TINUO
USLY CONVERT
ON
CONSECUTIVE SEQUENC
E
OF CHANNE
LS.
DIN: WRI
TE TO CONTROL
REGISTER TO STO
P THE
SEQUENCE, Se
q1 = 0, Seq2 = 0.
D
OUT: CON
VERSION RESULT
FR
OM CHANNEL IN SEQUENCE.
C
S
STOPPING
A SEQUE
NCE.
05400-032
Figure 45. Flowchart for Consecutive Sequence of Channels