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SPI Protocol Analysis

Step 1: Double click icon of LAP-32128U-A_STD to run the software

Step 2: Click “OK” to load the last file used or click “Cancel” to create a new file capturing data from the window of LogicAnalyzer appears.

Step 3: When software interface appears, please follow setup process below:

1.      Go to setup “RAM size” which 2K、16K、32K、64K、128K are provided. User could select the RAM size meeting requirement. We are selecting 128K here.

2.      Go to setup suitable “sample rate” which should be setup at least four times higher then the frequency of the Oscillator on the device under test. In this case the frequency is 12MHz, 12MHz*4=48 MHz, then select 50MHz as sample rate here.

3.  Go to setup trigger position at 10% to view the data before triggering.

Step 4: Go to “Bus/Signal” and selecting channel setup  , the window of channels setup will appear. Please follow the processes below to setup and rename the channels.

1.        Go to click “Delete All”to clearing up all channels.

2.        Go to click “Add Bus/Signal” thrice getting “New0”、“New1”and “New2” channels.

3.        Highlight “Port A0” to set “New2” cannel, Highlight “Port A1” to set “New1” channels, and highlight “Port A2” to set “New2” channels.

4.        Go to re-name “New0” into “MOSI”, go to re-name “New1” into “CS”, go to re-name “New2” into “CLK”.

Step 5: Go to setup the trigger condition as falling edge on the CS channel for the SPI signal.

Step 6: Go to click the Single Run  icon to turn on the logic analyzer capturing the data, then turn on the tested device. The logic analyzer is going to capture and calculate signals. As soon as the data has been stored in RAM, then system displays the wave.

Step 7: When the system completes the wave display, then go to click   to show all data which is displayed at better way to be looked.

Step 9: Go to click “Place T bar to the center” icon, the trigger point of the SPI wave decoded are shifted to the center of screen.

Step 8: Go to click the SPI  icon, the window of SPI setting is displayed to setup SPI conditions.

1.      Go to click “Customize”, the window of customize setup will appear for you to set your SPI condition required, then click “OK” to go back to the window of SPI Setting.

2.      Go to click the data format is required, for example, we are selecting ASCII here.

3.      Go to click off of “MISO” function.

4.      Go to setup the “CPHA” and “CPOL” mode from pull down menu of “MOSI”, for example, we are selecting “CPHA=0, CPOL=0” here.

5.      Go to click “start” then click “OK” to decode I²C protocol, when all conditions are set.

Step 10: Go to click Zoom in  icon, adjust the wave into the better ratio to view.

Step 11: Go to click the roll to shift and view the wave.