MAX11800_10 Datasheet, PDF (42/57 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
• Direct Conversion Read Operations (MAX11801/
MAX11803)
In direct conversion mode, commands automatically
set the readback target register and streamline data
gathering. See the Command and Register Maps sec-
tion for specific details for all such commands. The
MAX11801/MAX11803 automatically set the default
readback register to the XMSB location when a com-
mand requesting is received and a XY combined mea-
surement is received. If the XY command is issued and
allowed to complete, the device can then be followed
directly by a streamlined read sequence and data
readback commences from the XMSB register.
Accepted direct conversion commands always modify
the current internal register location and effectively
override the resumed readback behaviors and any reg-
ister settings made in response to previously complet-
ed direct conversion commands.
• Read Operations Following Write Operations
(MAX11801/MAX11803)
Data readback commences from the last written register
location when the streamlined readback sequence is
issued following a configuration write operation. When
modifying the contents of the operating mode configura-
tion register (0x0B) using a write sequence, then issuing
a streamlined readback sequence, the contents of regis-
ter 0x0B are provided. Register write operations always
modify the current internal register location and effectively
override the resumed readback behaviors.
I²C Conversion Command (MAX11801/MAX11803)
Figure 26 shows the required command format for issu-
ing conversion requests. A conversion request cannot
be paired with multiple commands or instructions. Any
conversion command issued while previous commands
are being executed is ignored and the readback 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 only (MAX11800/
MAX11801)
• Allows reading FIFO contents when operating in
ACM
3) Data Readback Commands: 52h to 5Bh
• Direct conversion mode only (MAX11800/
MAX11802)
• Allows reading measurement results when in DCM
START
SDA
SCL
WRITE ADDRESS
BYTE 1: DEVICE ADDRESS
CONVERSION COMMAND
1 0 0 1 0 A1 A0 W A N N N N N N N N A
STOP
Figure 26. I²C Conversion Command
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