LM8300IMT9 National Semiconductor, LM8300IMT9 Datasheet - Page 12
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LM8300IMT9
Manufacturer Part Number
LM8300IMT9
Description
IC TOUCHSCREEN CONTROLLR 48TSSOP
Manufacturer
National Semiconductor
Type
Resistiver
Datasheet
1.LM8300HVA9.pdf
(20 pages)
Specifications of LM8300IMT9
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
48-TSSOP
Voltage Supply Source
Single Supply
For Use With
LM8300-REF-01 - BOARD EVALUATION LM8300
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Sampling Rate (per Second)
-
Other names
*LM8300IMT9
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
LM8300IMT9B/NOPB
Manufacturer:
NS/TI
Quantity:
8
www.national.com
9.0 Functional Description
lines. This option can be used in high noise environments to
significantly improve performance and accuracy of the touch
screen controller.
The default setting is filter path enabled.
$A2: Toggle disable/enable self-power down
This command can switch between self-power down mode
enable or disabled. Refer to the Power Save Mode section
for details. The default setting is Self-Power Down mode
enabled. If the echo mode is enabled, any command byte
send to the device will be echo back and executed.
$A3: Toggle disable/enable echo mode
The echo mode is available for debugging purposes. If en-
abled, the touch screen controller will echo back any data
that is received via the UART interface.
The default setting is Echo mode disabled.
$A4: Toggle disable/enable pressure measurement
The pressure measurement sets the touch screen to also
sample the Z-axis when reading the X and Y coordinates.
The default setting is pressure measurement enabled.
$A5: Toggle disable/enable calibration checking.
If the cablibration checking is enabled, the cablibration map-
ping must be the values shown in ??? to ???.
$A7: Wakeup
There is no reply byte to this command.
When the self-power down mode of the device is enabled,
the touch screen driver must send a wakeup command prior
to any command byte(s). If the self-power down mode of the
TSC is enabled. The wakeup command must also to be sent
if the driver puts the TSC in power-down mode via the
shutdown command.
$A8: Shutdown
When the TSC driver wants the controller to go into power
save mode it sends a shutdown command to the controller.
The driver needs to send a wakeup to the controller before
starting up the communication again.
With the TSC has the self-power-down mode enabled, then
a touchdown on the touch screen will wake-up the TSC from
shutdown mode in addition to sending the wake up com-
mand. If the self-power-down mode is disabled, then only the
wakeup command can wake-up the controller from shut-
down mode (i.e. wake-up on touchdown is disabled).
$AF: Soft reset (restart the controller)
When the PC driver sends the soft reset command, the
touch screen controller executes a soft reset, which clears
and re-initializes all internal RAM configuration registers
from on-chip FLASH and performs a self-check of internal
RAM and program memory.
Reply Byte #1: $CA (Acknowledge)
Byte #2: (0 = now disabled, 1 = now enabled)
Reply Byte #1: $CA (Acknowledge)
Byte #2: (0 = now disabled, 1 = now enabled)
Reply Byte #1: $CA (Acknowledge)
Byte #2: (0 = now disabled, 1 = now enabled)
Reply Byte #1: $CA (Acknowledge)
Byte #2: (0 = now disabled, 1 = now enabled)
Reply Byte #1: $CA (Acknowledge)
Reply Byte #1: $CA (Acknowledge)
Byte #2: $CB/$CC (Self test OK/Self test fail)
(Continued)
12
CONTROLLER REPLIES
$CF: Timeout.
Communication timeout has occurred, and current command
has been aborted.
$CE: Re-send
Request the TSC driver to resend the last command. This
command is used if the controller does not understand the
received command or a buffer overrun condition occurs.
$CC: Self test fail (done at startup, reset, and after
$CB: Self test OK (done at startup, reset, and after
$CA: Acknowledge
$C4: Calibration coordinates OK
This is sent if the coordinates are within the predefined
value.
$C8: Error / TX Buffer overrun
This is added to the last place in transmit buffer to signal that
a buffer overrun has occurred.
$C7: Software Version number
$80: Format tablet for Z-axis disabled (see Format Table
$90: Format tablet for Z-axis enabled (see Format Table
10.0 Oscillator
OSC_IN is the clock input while OSC_OUT is the clock
generator output to the crystal. Table 1. Crystal Oscillator
Configuration,
T
for various standard crystal values. Figure 2 shows the
crystal oscillator connection diagram.
A
= 25˚C, V
section for more info.)
Byte #2: Status, low X and low Y
Byte #3: High X
Byte #4: High Y
section for more info.)
Byte #2: Status, low X and low Y
Byte #3: High X
Byte #4: High Y
Byte #5: Z-axis (0-127)
Byte #2: First byte of version number
Byte #3: Second byte of version number
Byte #4: Third byte of version number
calibration)
calibration)
CC
FIGURE 2. Crystal Oscillator
= 5V shows the component values required
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