Tenma 72-14520 Instructions Manual page 20

corresponding number of the present selected data. The selected decoding data will
be highlighted green. The multi-purpose control can select any collected data. This
function can find the content of captured multiple transmission communication and
help to debug the system conveniently.
• Input the signal as shown the figure below. The oscilloscope is set up as follows.
SCL selection is CH1. SDA selection is CH2. The condition is Addr. The set address
is 7bits, 0x48 and the direction is writing. The data do not need to be set because
data trigger is used.
• The bus status is open during setting the bus. The displayed format is ASCII. Open
the event selection and the display is as follows:
SPI Protocol Trigger and Decode (Optional)
• SPI interface is a kind of synchronized serial peripheral interface, which can make
the host and all kinds of peripheral equipment undertake communication through
the serial methods. It is a kind of synchronous communication bus of full duplex.
It usually uses four signal lines: MOSI: the host data output, the slave data input;
MISO: the host data input, the slave output; SCLK: time signal the host transmits;
CS: the slave chip selection enable signal.
• SPI interface is mainly used to transmit the serial data between the host and low
speed peripheral devices. The data are transmitted according to the bit, that is to
say, higher bit first and then lower bit. SPI interface do not need look for the slave
address. The communication is of full duplex and the protocol itself is easier. So it is
widely used. SPI protocol transmission is shown in the following diagram:
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