I2C Decode (Optional) - UNI-T UPO3000E Series User Manual

(3) Even List: Displays the decoded data, corresponding line number , time
and error information of the data line in a tabular form for easily observe
the longer decoded data.
(4) Pseudo Square Wave: Select on and the bus shows a square wave with
logic 1 for high level and logic 0 for low level.
(5) Vertical Position: Adjust the Multipurpose knob to change the bus display
position.
(6) Data Packet: After the device is paused, user can view the decoded data
packets.
Trigger Setting:
Please refer to the Trigger Setting in the "Edge Trigger" section for more details.

6.2 I2C Decode (Optional)

I2C protocol is usually used to connect a microcontroller and its peripheral
equipment, and it is widely used in the field of microelectronics communication
control. The bus protocol uses two lines to transmit. One is serial data line
SDA, the other is serial clock line. The HOS-SLAVE mechanism is adopted,
which is a 2-way communication between host and slave. The bus is multi-host
which prevents data destruction through collision detection and arbitration
mechanism. It's remarkable that I2C bus has two kinds of address width: 7
bits and 10 bits. The two are compatible and can be combined. Both SCL
and SDA are connected to power through pull-up resistors. When the bus
is vacant, the two lines are at high level. When any component of bus outputs
low level, the bus signals will become low. That is to say, the signals of
multi-components are wired AND logic. The special logic relationship is the
key point to realize bus arbitration. The protocol requires that data SDA should
keep stable when clock line SCL is high. Normally, the data is transmitted
by MSB format, as shown below:
I2C Selection:
Press DECODE type, and select I2C by the Multipurpose knob. You
can also switch the trigger type by consecutively pressing the type key, then
press the Multipurpose knob to confirm.
SCL Source:
Press the SCL source key to select the SCL source, you can set any of
CH1~CH4 as the clock input of I2C.
SDA source:
Press the SDA source key to select the SDA source, you can set any of
CH1~CH4 as the data input of I2C.
Address Mode:
Press the address key to select the address mode and set the address bit
width of I2C signal that needs to be triggered, you can select 7bits or 10bits.
Operation Direction:
Press PgDn operation direction to select write or read.
(1) Write: Triggers when the "read/write" bit of the I2C protocol is "write".
(2) Read: Triggers when the "read/write" bit of the I2C protocol is "read".
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