AD7877 Analog Devices, AD7877 Datasheet - Page 23

• Manufacturer Part Number: AD7877
• Description: Touch Screen Controller
• Manufacturer: Analog Devices

Specifications of AD7877

• Resolution (bits): 12bit
• # Chan: 9
• Sample Rate: 125kSPS
• Interface: Ser
• Analog Input Type: SE-Uni
• Ain Range: Uni (Vref),Uni 2.5V
• Adc Architecture: SAR
• Pkg Type: CSP

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