Datasheet

Data Sheet AD7877
Rev. D | Page 23 of 44
03796-016
LIMIT COMPARISON
START FCD TIMER
UPDATE ALERT
ENABLE/STATUS
REGISTER
CONVERT
SELECTED CHANNEL
IS FCD
FINISHED?
HOST PROGRAMS
AD7877 IN MODE 01
NO
YES
NO
YES
NO
YES
YES
NO
YES
NO
IS AVERAGING
FINISHED?
ONCE-ONLY
MODE?
WRITE RESULT TO
REGISTERS
GO TO MODE 00
ALERT
SOURCE
ENABLED?
IS ACQUISITION
TIME FINISHED?
TIMER
FINISHED?
IS FCD
REQUIRED?
START ACQUISITION TIMER
START TIMER
OUT-OF-LIMIT?
ASSERT ALERT
OUTPUT
1
YES
NO
NO
YES
YES
NO
1
SEE SEQUENCER REGISTERS SECTION.
IS STOPACQ
SIGNAL ACTIVE?
NO
IS STOPACQ
SIGNAL ACTIVE?
NO
YES
YES
Figure 38. Single Channel Operation
03796-017
YES
NO
ONCE-ONLY
MODE?
GO TO MODE 00
TIMER
FINISHED?
START TIMER
NO
YES
1
SEE SEQUENCER REGISTERS SECTION.
LIMIT COMPARISON
START FCD TIMER
UPDATE ALERT
ENABLE/STATUS
REGISTER
CONVERT
SELECTED CHANNEL
IS FCD
FINISHED?
HOST PROGRAMS
AD7877 IN MODE 10
NO
YES
NO
YES
NO
YES
YES
NO
IS AVERAGING
FINISHED?
WRITE RESULT TO
REGISTERS
ALERT
SOURCE
ENABLED?
IS ACQUISITION
TIME FINISHED?
IS FCD
REQUIRED?
START ACQUISITION TIMER
OUT-OF-LIMIT?
ASSERT ALERT
OUTPUT
1
YES
NO
YES
NO
VALID
SEQUENCE 0?
SELECT NEXT
CHANNEL
GO TO MODE 00
LAST CHANNEL
IN SEQUENCE?
YES
NO
YES
IS STOPACQ
SIGNAL ACTIVE?
NO
YES
IS STOPACQ
SIGNAL ACTIVE?
YES
NO
NO
Figure 39. Slave Mode Sequencer Operation