STMPE812ABJR STMicroelectronics, STMPE812ABJR Datasheet - Page 12

• Manufacturer Part Number: STMPE812ABJR
• Description: Touch Screen Converters & Controllers Touchscreen cntrlr S-Touch
• Manufacturer: STMicroelectronics
• Type: Resistive Touch Controllersr

Specifications of STMPE812ABJR

• Rohs: yes
• Input Type: 1 TSC
• Data Rate: 400 kbps
• Resolution: 12 bit
• Interface Type: 4-wire, I2C
• Supply Voltage: 1.65 V to 3.6 V
• Supply Current: 100 uA
• Operating Temperature: - 40 C to + 85 C
• Package / Case: CSP-12
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 1.65 V

I2C interface
2.3
2.4
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Read operation
A write is first performed to load the register address into the Address Counter but without
sending a Stop condition. Then, the bus master sends a reStart condition and repeats the
Device Address with the R/W bit set to 1. The slave device acknowledges and outputs the
content of the addressed byte. If no additional data is to be read, the bus master must not
acknowledge the byte and terminates the transfer with a Stop condition.
If the bus master acknowledges the data byte, then it can continue to perform the data
reading. To terminate the stream of data bytes, the bus master must not acknowledge the
last output byte, and be followed by a Stop condition. If the address of the register written
into the Address Counter falls within the range of addresses that has the auto-increment
function, the data being read is coming from consecutive addresses, which the internal
Address Counter automatically increments after each byte output. After the last memory
address, the Address Counter 'rolls-over' and the device continues to output data from the
memory address of 0x00. Similarly, for the register address that falls within a non-increment
range of addresses, the output data byte comes from the same address (which is the
address referred by the Address Counter).
Acknowledgement in read operation
For the above read command, the slave device waits, after each byte read, for an
acknowledgement during the ninth bit time. If the bus master does not drive the SDA to a
low state, then the slave device terminates and switches back to its idle mode, waiting for
the next command.
Write operations
A write is first performed to load the register address into the Address Counter without
sending a Stop condition. After the bus master receives an acknowledgement from the slave
device, it may start to send a data byte to the register (referred by the Address Counter).
The slave device again acknowledges and the bus master terminates the transfer with a
Stop condition.
If the bus master needs to write more data, it can continue the write operation without
issuing the Stop condition. Whether the Address Counter autoincrements or not after each
data byte write depends on the address of the register written into the Address Counter.
After the bus master writes the last data byte and the slave device acknowledges the receipt
of the last data, the bus master may terminate the write operation by sending a Stop
condition. When the Address Counter reaches the last memory address, it 'rolls-over' to the
next data byte write.
Doc ID 18225 Rev 4
STMPE812A