EVAL-AD7877EBZ Analog Devices Inc, EVAL-AD7877EBZ Datasheet - Page 40

• Manufacturer Part Number: EVAL-AD7877EBZ
• Description: BOARD EVALUATION FOR AD7877
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD7877EBZ

• Main Purpose: Interface, Touch Screen Controller
• Embedded: No
• Utilized Ic / Part: AD7877
• Primary Attributes: 4-Wire Resistive Touch Screen Controller, SPI Interface, On-Chip: Temp Sensor, Voltage Reference, 8-Bit DAC
• Secondary Attributes: USB GUI, LCD Noise Reduction Feature, 2.7 ~ 5.25 V, Wake Up on Touch Feature
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD7877
Register Name: TEMP1
Write Address: N/A; Read Address: 11000;
Default Value: 0x000; Type: Read Only.
This register contains the 12-bit result of a temperature
measurement using single-ended conversion.
Register Name: TEMP2
Write Address: N/A; Read Address: 11001;
Default Value: 0x000; Type: Read Only.
This register contains the 12-bit result of a temperature
measurement using a differential conversion.
Register Name: GPIO Control Register 1
Write Address: [1111] 0000; Read Address: 11011; Default Value: 0x000; Type: Read/Write.
Table 22.
Bit
0
1
2
3
4
5
6
7
Name
GPIO2_ALEN
GPIO2_DIR
GPIO2_POL
GPIO2_EN
GPIO1_ALEN
GPIO1_DIR
GPIO1_POL
GPIO1_EN
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
If this bit is 1, GPIO2 is an interrupt source for the ALERT output; clearing this bit masks out GPIO2
as an interrupt source for the ALERT output
This bit sets the direction of GPIO2
This bit determines if GPIO2 is active high or low
This bit selects the function of AUX2/GPIO2
If this bit is 1, GPIO1 is an interrupt source for the ALERT output; clearing this bit masks out GPIO1
as an interrupt source for the ALERT output
This bit sets the direction of GPIO1
This bit determines if GPIO1 is active high or low
This bit selects the function of AUX1/GPIO1
0 = output
1 = input
0 = active low
1 = active high
0 = AUX2
1 = GPIO2
0 = output
1 = input
0 = active low
1 = active high
0 = AUX1
1 = GPIO1
Rev. B | Page 40 of 44
Register Name: Z1
Write Address: N/A; Read Address: 11010;
Default Value: 0x000; Type: Read Only.
This register contains the 12-bit result of a measurement at the
X+ input with excitation voltage applied to Y+ and X− (used for
touch-pressure calculation).
GPIO REGISTERS
GPIO registers are written to using an extended 8-bit address.
The first four bits of the data-word are always 1111b to access
the extended writing map. The next four bits are the register
address. This leaves 8 bits for the GPIO data.
GPIO registers are read like all other registers, by writing a 5-bit
address to Control Register 1, then reading DOUT.
See the GPIO Configuration section for information on
configuring the GPIOs.