AD7877 Analog Devices, AD7877 Datasheet - Page 35

• 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
DETAILED REGISTER DESCRIPTIONS
Register Name: Control Register 1
Write Address:
Read Address:
Default Value:
Type:
Table 16.
Bit
0
1
2
3
4
5
6
7
8
9
10
11
Name
MODE0
MODE1
RD0
RD1
RD2
RD3
RD4
CHADD0
CHADD1
CHADD2
CHADD3
SER/DFR
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0001
00001
0x000
Read/write
Description
LSB of ADC mode code
MSB of ADC mode code
00 = no conversion
01 = single conversion
10 = conversion sequence (slave mode)
11 = conversion sequence (master mode)
LSB of register read address; to read a register, its address must first be written to Control Register 1
Bit 1 of register read address; to read a register, its address must first be written to Control Register 1
Bit 2 of register read address; to read a register, its address must first be written to Control Register 1
Bit 3 of register read address; to read a register, its address must first be written to Control Register 1
MSB of register read address; to read a register, its address must first be written to Control Register 1
LSB of ADC channel address
Bit 1 of ADC channel address
Bit 2 of ADC channel address
MSB of ADC channel address
0000 = X+ input (Y position)
0001 = Y+ input (X position)
0010 = Y− (Z2) input (used for touch-pressure calculation)
0011 = Auxiliary Input 1 (AUX1)
0100 = Auxiliary Input 2 (AUX2)
0101 = Auxiliary Input 3 (AUX3)
0110 = Battery Monitor Input 1 (BAT1)
0111 = Battery Monitor Input 2 (BAT2)
1000 = Temperature Measurement 1 (used for single conversion)
1001 = Temperature Measurement 2 (used for differential measurement method)
1010 = X+ (Z1) input (used for touch-pressure calculation)
Selects normal (single-ended) or ratiometric (differential) conversion
0 = ratiometric (differential)
1 = normal (single-ended)
Rev. D | Page 35 of 44
AD7877