Datasheet

AR1000 SERIES RESISTIVE TOUCH SCREEN CONTROLLER
DS41393B-page 42 Preliminary  2009-2012 Microchip Technology Inc.
9.3.10 EEPROM_WRITE – 0x29
The controller has 256 bytes of on-board EEPROM.
This command provides a means to write values to the
user space within the EEPROM.
• The first 128 bytes (address range 0x00-0x7F)
are reserved by the controller for the Configura-
tion register settings and calibration data. Only the
Register Write to EEPROM command should be
used to write Configuration registers to EEPROM.
Failure to use the Register Write command to
save Configuration registers to EEPROM may
result in failures or reverting to previously stored
Configuration register values.
• The second 128 bytes (address range
0x80-0xFF) are provided for the user’s applica-
tion, if desired.
Write to EEPROM as follows:
Send: <0x55><0x04 + # EEPROM to
Write><0x29><EEPROM Address High
byte><EEPROM Address Low byte>
<# of EEPROM to
Write><Data>…<Data>
Register Address High byte: 0x00
# of Registers to Read: 0x01 thru 0x08
Receive: <0x55><0x02><Response><0x29>
The AR1000 controller will ignore the value entered for
the EEPROM Address High Byte. However, 0x00 is
recommended to safeguard against any possible future
product development.
9.3.11 EEPROM_WRITE_TO_REGISTERS –
0x2B
Write applicable EEPROM data to Configuration regis-
ters. This will cause the controller to immediately begin
using changes made to EEPROM stored Configuration
register values. A power cycle of the controller will
automatically cause the controller to use changes
made to the EEPROM stored Configuration register
values, without the need for issuing this command. This
command eliminates the need for the power cycle.
Send: <0x55><0x01><0x2B>
Receive: <0x55><0x02><Response><0x2B>
9.3.12 EEPROM MAP
The first 128 bytes in address range 0x00:0x7F are
reserved by the controller for the Configuration register
settings and calibration data. The mapping of data in
this reserved controller space of the EEPROM may
change over different revisions within the product
lifetime.
The EEPROM_WRITE command must not be used to
write directly to the lower 128 bytes of the controller
EEPROM space of 0x00:0x7F.
The second 128 bytes in address range 0x80:0xFF are
provided for the user’s application, if desired.
Warning: ONLY write to user EEPROM addresses of
0x80-0xFF.
One of the following actions is required for
EEPROM changes to be used by the
controller:
• The controller power must be cycled
from OFF to ON or
• Issue the
EEPROM_WRITE_TO_REGISTERS
command.
TABLE 9-6: AR1010/AR1020 EEPROM
AND REGISTER MAP
EEPROM Address Function
0x00 <Special Use>
0x01 <Special Use>
0x02 <Special Use>
0x03 Touch Threshold
0x04 Sensitivity Filter
0x05 Sampling Fast
0x06 Sampling Slow
0x07 Accuracy Filter Fast
0x08 Accuracy Filter Slow
0x09 Speed Threshold
0x0A <Special Use>
0x0B Sleep Delay
0x0C Pen-Up Delay
0x0D Touch Mode
0x0E Touch Options
0x0F Calibration Inset
0x10 Pen State Report Delay
0x11 <Reserved>
0x12 Touch Report Delay
0x13 <Special Use>
0x14 Data Block Separator
0x15 Calibration UL X-low
0x16 Calibration UL X-high
0x17 Calibration UL Y-low
0x18 Calibration UL Y-high
0x19 Calibration UR X-low
0x1A Calibration UR X-high
0x1B Calibration UR Y-low
0x1C Calibration UR Y-high
0x1D Calibration LR X-low
0x1E Calibration LR X-high
0x1F Calibration LR Y-low