MAX11800_1010 Datasheet, PDF (45/59 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
START
SDA
SCL
WRITE ADDRESS
BYTE 1: DEVICE ADDRESS
CONVERSION OR MEASUREMENT COMMAND
1 0 0 1 0 A1 A0 W A N6 N5 N4 N3 N2 N1 N0 X A
STOP
Figure 30. I²C Conversion and Measurement Commands
Direct Conversion Read Operations
All direct conversion commands automatically set the
readback target register, streamlining data gathering
operations. See the register map for specific details for
all such commands. For example, if the user writes a
command requesting an XY combined measurement,
the MAX11801/MAX11803 automatically set the default
readback register pointer to the XMSB location. Thus, if
the XY command is issued and allowed to complete, it
can then be followed directly by a streamlined read
sequence of the format, as shown in Figure 29, and
newly acquired data is read back, commencing with
the XMSB register.
Note that accepted direct conversion commands
always modify the current internal register location and
effectively override the resumed readback behaviors
and any register settings made in response to previous-
ly completed direct conversion commands. Users wish-
ing to override this behavior can use still use the
standard readback sequences of the format, as shown
in Figures 28 and 29.
Read Operations Following Write Operations
If the streamlined readback sequence is issued follow-
ing a configuration write operation, data readback com-
mences from the last written register location. Thus, if
the user modifies the contents of the Operating Mode
Configuration register (0x0B) using a write sequence
and then issues a streamlined readback sequence, the
contents of register 0x0B are provided.
Note that register write operations always modify the
current internal register location and effectively override
the resumed readback behaviors.
I²C Conversion and Measurement
Commands (MAX11801/MAX11803)
Figure 30 shows the required command format for
issuing conversion and measurement requests. A
request cannot be paired with multiple commands or
instructions. Any command issued while previous com-
mands are being executed is ignored and the read-
back target register is not modified.
Command and Register Map
The command map consists of the user-configuration reg-
isters (read/write), TSC data readback commands (read
only), and TSC panel setup and conversion commands
(write only).
User-Accessible Registers
There are six blocks of user-accessible registers and
commands that control all operations of the
MAX11800–MAX11803. The register blocks and com-
mands consist of the following:
1) Status and Configuration Registers: 00h to 0Bh
• Sets modes of operation––ACM or DCM
• Settings to accommodate various panel sizes
(panel time constant)
• Averaging and noise settings
• Measurement resolution
• Auxiliary settings
• General part status reporting
2) FIFO Data Readback Command: 50h
• Autonomous conversion mode (MAX11800/
MAX11801)
• Allows reading FIFO contents when operating in
ACM (MAX11800/MAX11801)
3) Data Readback Commands: 52h to 5Bh
• Direct conversion mode (MAX11800/MAX11802)
• Allows reading measurement results when in DCM
4) I²C Readback Registers: 52h to 58h
• Direct conversion mode (MAX11801/MAX11803)
• Allows reading measurement results when in DCM
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