LM8500HVA9 National Semiconductor, LM8500HVA9 Datasheet - Page 18

• Manufacturer Part Number: LM8500HVA9
• Description: IC TOUCHSCREEN CONTROLLER 44PLCC
• Manufacturer: National Semiconductor
• Type: Resistiver

Specifications of LM8500HVA9

• Touch Panel Interface: 4-Wire
• Number Of Inputs/keys: 1 TSC
• Resolution (bits): 10 b
• Data Interface: UART
• Data Rate/sampling Rate (sps, Bps): 38.4k
• Voltage - Supply: 2.7 V ~ 5.5 V
• Current - Supply: 11.5mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 44-PLCC
• Voltage Supply Source: Single Supply
• For Use With: LM8500-REF-01 - BOARD EVALUATION LM8500
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Sampling Rate (per Second): -
• Other names: *LM8500HVA9

www.national.com
October 2002
May 2003
July 2003
December
2003
14.0 Calibration
send a reply byte of $CC to the TS driver. At this point, the
TS driver should either notify the user to redo the calibration
point or automatically redo the calibration again. If the self-
test was successful, the device will send a reply byte of $CB
to the TS driver.
14.3 CALIBRATION PROCEDURES WITH
COORDINATES CHECKING DISABLED
To do TS calibration with coordinates checking disabled, first
ensure the Calibration Coordinates Checking is disabled on
the device. This can be accomplished by sending a com-
mand byte of $B1 (Read Parameters command) and check-
ing the 5th bit of the 12th reply byte is not set. Alternatively,
if the device is set to Calibration Coordinates Checking
disabled as default, this step can be skipped.
The TS driver sends the command byte to do calibration
($BD). The TS driver should wait for the reply bytes and
15.0 Revision History
Date
All sections
Brownout Reset
Advanced Command Bytes
Descriptions
Advanced Command Bytes
Descriptions
Section
(Continued)
Initial release.
Removed LM8400 part.
Updated section to reflect the change and made external reset circuitry
optional.
Added command byte $A5
Updated controller reply bytes
Added description for command byte $A5
18
ensure it is the same command bytes it sent. The device
waits for a touch to be detected on the panel. Once a touch
is detected, the device save the values into the internal flash
and send a reply byte of $C4 to the TS driver. The TS driver
can now send a command byte to do the next calibration
point. Since the Calibration Checking is disabled, the TS
driver should ensure the calibration point is within the range
of the calibration cross.
Once all the calibration points are done, the device does a
self-test. If the self-test was not successful, the device will
send a reply byte of $CC to the TS driver. At this point, the
TS driver should either notify the user to redo the calibration
point or automatically redo the calibration again. If the self-
test was successful, the device will send a reply byte of $CB
to the TS driver.
Summary of Changes