![](http://datasheet.mmic.net.cn/230000/LM8300HVA9_datasheet_15593334/LM8300HVA9_10.png)
9.0 Functional Description
(Continued)
PC
Command
PC
Byte
1
$B4
PC
Byte 2
TSC
Byte 1
TSC
Byte 2
Read stored
calibration
points
$CA
Section
9.3.3
Advanced
Command
Bytes
Descriptions
$00-$3F
Set focus
value (# of
pixels on
touch panel)
Set # of
samples per
coordinate (1,
2, 4, 8, 16,
32)
Set
communication
mode
(stream,
touchdown,
liftoff)
Set max delta
(# of pixels
from
predicted
coordinate)
Set calibration
points
$B8
$0-$3F
$CA
$BA
$01, $02,
$04, $08,
$10, $20
$CA
$01, $02,
$04, $08,
$10, $20
$BB
$01, $02,
$04
$CA
$01, $02,
$04
$BC
$00-$3F
$CA
$00-$3F
$BD
Section
9.3.3
Advanced
Command
Bytes
Descriptions
$00-$7F
$CA
Section
9.3.3
Advanced
Command
Bytes
Descriptions
$00-$7F
Set minimum
pressure
Toggle
disable/enable
external filter
path
Toggle
disable/enable
self
power-down
Toggle
disable/enable
echo mode
Toggle
disable/enable
pressure
measurements
$BE
$CA
$A0
$CA
$00, $01
$A2
$CA
$00, $01
$A3
$CA
$00, $01
$A4
$CA
$00, $01
PC
Command
PC
Byte
1
$A5
PC
Byte 2
TSC
Byte 1
TSC
Byte 2
Toggle
disable/enable
calibration
coordinate
check
Wakeup
Shutdown
Soft reset
TSC Replies
Timeout
Re-send
Self test failed
Self test ok
Acknowledge
Calibration
coordinates
ok
Error / buffer
overrun
Software
version
Data transmit
$CA
$00, $01
$A7
$A8
$AF
$CA
$CA
$CB, $CC
$CF
$CE
$CC
$CB
$CA
$C4
$C8
$C7
$0-$7F
$80/$90Payload (3/4
bytes)
9.3.3 Advanced Command Bytes Descriptions
Unless otherwise mentioned, all values are in hex.
$B0: Read clock-speed
Reply Byte #1: $CA (Acknowledge)
Byte #2: Clock readout (0 = 3.3MHz, 1 = 10MHz)
CLK_SEL pin tells the firmware which oscillator speed is
used. If the CLK_SEL input pin is floating or pulled high a
10.0MHz oscillator must be connected. If the pin is pulled
low a 3.3MHz oscillator must be connected. This command
enables the driver software to determine which oscillator
speed is used with the touch screen controller, as this deter-
mines the maximum coordinate pair per second data rates.
Note:
This is available in the LM8500 only.
$B1: Read parameters
Reply Byte #1: $CA (Acknowledge)
Reply Byte #2: First byte in software version number,
year 20 (00-99)
Reply Byte #3: Communication mode (1 = stream, 2 =
touchdown, 4 = liftoff)
Byte #4: Wakeup on touch (0 = disabled, 1 = enabled)
Reply Byte #5: Number of samples (1,2, 4, 8, 16 or
32)
Byte #6: Clock readout (0 = 3.3MHz, 1 = 10MHz)
Byte #7: Second byte in software version number,
month (1-12)
Byte #8: Third byte in software version number, day
(1-31)
Byte #9: Focus value (0-63)
Byte #10: Max delta (0-63)
L
www.national.com
10