AD7877 Analog Devices, AD7877 Datasheet - Page 34

• 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

AD7877
Table 15. Read Register Map
RADD4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
RADD3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Register Address
RADD2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Binary
RADD1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
RADD0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Hex
00
01
02
03
04
05
06
07
08
09
0A
0B
0C
0D
0E
0F
10
11
12
13
14
15
16
17
18
19
1A
1B
1C
1D
1E
1F
Rev. D | Page 34 of 44
Register Name
None
Control Register 1
Control Register 2
Alert status/enable
register
AUX1 high limit
AUX1 low limit
BAT1 high limit
BAT1 low limit
BAT2 high limit
BAT2 low limit
TEMP1 low limit
TEMP1 high limit
Sequencer Register 0
Sequencer Register 1
DAC register
None
X+
Y+
Y− (Z2)
AUX1
AUX2
AUX3
BAT1
BAT2
TEMP1
TEMP2
X+ (Z1)
GPIO Control
Register 1
GPIO Control
Register 2
GPIO data
None
None
Description
Reads back all zeros
See Table 13
See Table 13
See Table 13
See Table 13
See Table 13
See Table 13
See Table 13
See Table 13
See Table 13
See Table 13
See Table 13
See Table 13
See Table 13
See Table 13
Factory use only
Measurement at X+ input for Y position
Measurement at Y+ input for X position
Measurement at Y− input for touch-pressure
calculation Z2
Auxiliary Input 1 measurement
Auxiliary Input 2 measurement
Auxiliary Input 3 measurement
Battery Input 1 measurement
Battery Input 2 measurement
Single-ended temperature measurement
Differential temperature measurement
Measurement at X+ input for touch-pressure
calculation Z1
See Table 14
See Table 14
See Table 14
Factory use only
Factory use only
Data Sheet