MAX11800 Datasheet, PDF (28/56 Pages) Maxim Integrated Products – Low-Power, Ultra-Small Resistive Touch-Screen Controllers with I2C/SPI Interface

Low-Power, Ultra-Small Resistive Touch-Screen
Controllers with I²C/SPI Interface
Table 9. Panel Measurement Command Summary
HEX R7 R6 R5 R4 R3 R2 R1
R0 _{ACCESS PAIRABLE} COMMAND
(CONT)
LENGTH
FUNCTION
7xh 0 1 1 1 0 0 0
(0)
Write
No
8
X, Y = combined command
measurement
7xh 0 1 1 1 0 0 1
(0)
Write
No
8
X, Y, Z1 = combined
command measurement
7xh 0 1 1 1 0 1 0
(0)
Write
No
7xh 0 1 1 1 0 1 1
(0)
Write
No
7xh 0 1 1 1 1 0 0 CONT Write
No
7xh 0 1 1 1 1 0 1 CONT Write
No
7xh 0 1 1 1 1 1 0 CONT Write
No
7xh 0 1 1 1 1 1 1 CONT Write
No
8
X, Y, Z1, Z2 = combined
command measurement
8
AUX = conversion
8
X = measurement
8
Y = measurement
8
Z1 = measurement
8
Z2 = measurement
When using a measurement command with CONT = 1 in
a direct conversion mode, the MAX11800–MAX11803
perform a data tagging operation at the conclusion of the
command. The devices remain in the requested setup
mode in preparation for the succeeding measurement.
The panel does not return to TDM/LPM and the interrupt
status is not modified as a result of a measurement com-
mand with CONT = 1 issued. See Figure 12.
Combined Commands
In direct conversion modes, the panel returns to a TDM
at the conclusion of a combined command and all data
are tagged accordingly. The MAX11800–
MAX11803 then idle in a low-power mode determined
by the interrupt mode selected. See Figure 13.
Auxiliary Measurement Command
The MAX11800–MAX11803 support measurement of an
auxiliary input using the internal ADC in direct conver-
sion mode only. When programmed, the devices sam-
ple and quantize the voltage at AUX using V_DD as the
ADC reference. The MAX11800–MAX11803 store the
result in the same manner as X, Y, Z1, and Z2 measure-
ments, but do not add data tagging. The devices also
support averaging functions. Auxiliary measurements
do not require any panel setup procedure. There is no
combined command which includes an auxiliary mea-
surement. Register 0x0A specifies the configuration for
auxiliary measurements.
In CINT, the MAX11800–MAX11803 continue to monitor
for the touch status of the panel. The devices report any
change in touch status in real time during an auxiliary
measurement procedure.
When performing auxiliary measurements in edge
interrupt mode, the MAX11800–MAX11803 temporarily
suspend the panel touch monitoring. The devices noti-
fy the AP after the completion of the auxiliary measure-
ment when a new touch occurs during the auxiliary
measurement.
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