NT1080 Datasheet, PDF (9/22 Pages) List of Unclassifed Manufacturers – 8-bit Microcontroller

NT1080
5 I²C INTERFACE
The maximum speed of I²C serial interface could be up to 400Kbps and it will not send any signal in
an active way to main controller since it is I²C slave. The I²C interface is not working in normal
operation time. To enter I²C serial mode, user must connect V_DD to SEL pin and then make chip
power-on. User could easily set the touch related parameter and adjust the sensitivity by using the
I²C interface.
The I²C transmission provides three modes: byte-write, random-read and continual-read.
5.1 Byte-Write
The data protocol includes 3 bytes from master writing data to salve. The first byte for Device
address, the second byte for Memory address and the third byte is for the write data. Figure 5-1
shows the detail about byte-write action.
SDA
SCL
Byte1 Device address Byte2 Memory address
Byte3 Data
Figure 5-1 Byte-write Mode
In normal times, SDA and SCL will be kept as logic 1. For the start signal, SDA will change to logic
0 first then SCL to logic 0 as well. When transmitting, data is prepared on SDA signal and then SCL
will change to logic 1. Slave reads the byte data based on the rising edge of SCL signal. Slave will
send logic 0 on the 9th clock signal to indicate receiving the byte data. For the stop signal, master
device will change SCL to logic 1 and then SDA to 1, when the transmission of 3 bytes of
information are finished.
5.2 Random-Read
This is a 4-byte data combination when Master reads Slave. Figure 5-2 shows that the first byte is
used as device address and write-status; the second byte is used as memory address; the third
byte is used as device address and read-status and the fourth byte is used as Slave output data
with Master keeping sending the SCL clock signal.
SDA
SCL
Byte1 Device address Byte2 Memory address
Byte3 Device address
Oct 26, 2015
Figure 5-2 Random-Read Mode
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Byte4 Data
Rev 1.0