AR1020T-I/SO Microchip Technology, AR1020T-I/SO Datasheet - Page 24

• Manufacturer Part Number: AR1020T-I/SO
• Description: IC TOUCH SCREEN CTRLR 20-SOIC
• Manufacturer: Microchip Technology
• Type: Resistiver

Specifications of AR1020T-I/SO

• Package / Case: 20-SOIC (7.5mm Width)
• Touch Panel Interface: 4-Wire, 5-Wire, 8-Wire
• Number Of Inputs/keys: 3 Key
• Resolution (bits): 10 b
• Data Interface: I²C, Serial, SPI™
• Voltage - Supply: 3.3 V ~ 5.5 V
• Current - Supply: 17mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Voltage Supply Source: Single Supply
• Supply Voltage Range: 3.135V To 3.465V, 4.75V To 5.25V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: SOIC
• No. Of Pins: 20
• Svhc: No SVHC (15-Dec-2010)
• Supply: RoHS Compliant
• Ic Function: Touch Screen Controller
• Rohs Compliant: Yes
• Resolution: 10 bit
• Interface Type: I2C, SPI
• Supply Voltage (max): 5 V
• Supply Voltage (min): 3.3 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sampling Rate (per Second): -
• Lead Free Status / Rohs Status: Details

7.15.3.1 How the Calibration Data is Encoded and Stored in EEPROM
This section is informational only. No user action is required.
The raw touch coordinates, decoded by the controller, for each of the four calibration touches are extrapolated if
CalibrationInset was non-zero. The four coordinate pairs are then re-oriented, if required, such that the upper left
corner is the minimum (X,Y) “origin” value pair and the lower right corner is the maximum (X,Y) value pair.
The manipulated calibration values are stored in 17 address locations of the EEPROM. In the EEPROM, the
calibration data follows the storage of the controller operating parameters. The controller operating parameters
and the calibration data are each preceded by a separator value of 0x55. Coordinates are 10-bit significant
values, scaled to 16-bit and stored in a Hi and Lo byte pair.
Address
Decode the above data to as follows:
1) Swap the order of stored Lo and Hi bytes for a given coordinate.
2) Convert the 16-bit value (stored Hi and Lo bytes) from hexadecimal to decimal.
3) Divide the result by 64 to properly rescale the 16-bit stored value back to a 10-bit significant coordinate.
Example of Lo = 0x40 and Hi = 0xF3:
Flip State Byte: R = Readable bit, W = Writable bit, U = Unimplemented bit read as ‘0’
Bit 7
bit 7-3 Unimplemented: Read as ‘0’
bit 2
bit 1
bit 0
DS41393A-Page 20
Value
U–0
–
Swap
Hex to Decimal : 62272
Divide by 64
XYFLIP: X and Y axis flip bit
1 = X and Y axis are flipped
0 = X an Y axis are not flipped
XFLIP: X-axis flip bit
1 = X-axis flipped
0 = X-axis not flipped
YFLIP: Y-axis flip bit
1 = Y-axis flipped
0 = Y-axis not flipped
Separator
0x55
0x14
U–0
–
0x15
Lo
Upper Left (Node 1)
: 0xF340
: 973
X
0x16
Hi
U–0
–
0x17
Lo
Y
0x18
Hi
U–0
–
0x19
Lo
Upper Right (Node 2)
X
0x1A
Hi
U–0
–
0x1B
Lo
Y
0x1C
Hi
XYFLIP
R/W
0x1D
Lo
Lower Right (Node 3)
X
0x1E
Hi
XFLIP
R/W
0x1F
Lo
© 2009 Microchip Technology, Inc.
Y
0x20
Hi
YFLIP
R/W
0x21
Lo
Bit 0
Lower Left (Node 4)
X
0x22
Hi
0x23
Lo
Y
0x24
Hi
Flip
State
0x25