Changes

The code is currently held in a separate repository at [https://github.com/newaetech/cw-apiexample1/tree/master/matlabrepository]. You'll have to clone that repository (or use the download link inside of GITHub) to copy the files into your own local working directory.

To run Since the examplesnew CW 4, you will need 0 API exposes the internals of chipwhisperer the easiest way to get access to ensure you set the chipwhisperer module in MATLAB working directory is to use this API. Run this command in MATLAB.<syntaxhighlight lang=matlab> >> [cw, scope, target] = cwconnect()</syntaxhighlight>or <pre> >> [cw, scope, target] = cwconnect(int64(1250), int64(3000))</pre>where the location first argument is the default offset, and the second argument is default number of samples. This command should return the 4.m script files0 API, scope object, and target object, each having their own interface. The following shows my example setup:

[[FileIf this works it should print the information about the 'cw', 'scope' and 'target' object:api_matlab_path.png]]<syntaxhighlight> cw =

The matlab files internally will reference a .py file in that same directory. You should be able to simply connect to the ChipWhisperer-Lite Python module with the followingproperties:

If this works it should print the information about the <module 'cwchipwhisperer' objectfrom 'c:\chipwhisperer\software\chipwhisperer\__init__.pyc'>

If this FAILS, you may need to simply unplug/replug the ChipWhisperer-Lite== 4. You may have not closed 0 API Notes ==Once the connection from the previous test<code>cwconnect. Note m</code> function is executed you can actually interact directly with have access to the 'cw' object as scope and target options, which are part of the new exposed API in Python<code>chipwhisperer</code>. For example we can get information about To list the current properties that are available type this inside your MATLAB interpreter:<pre> >> scope module</pre>This should print the MATLAb output for the scope object but python also prints the attributes you can change and customize. The output should look like this:<pre>scope =

>> cw.getScope()Python OpenADC with properties:

But you probably just want to run an AES test connectStatus: [1×1 py. To do this, simply perform the followingchipwhisperer.common.utils.util.Observable] scopetype:[1×1 py.chipwhisperer.capture.scopes.openadc_interface.naeusbchip.OpenADCInterface_NAEUSBChip] digitalPattern: [1×1 py.NoneType] adc: [1×1 py.chipwhisperer.capture.scopes._OpenADCInterface.TriggerSettings] params: [1×1 py.chipwhisperer.common.utils.parameter.Parameter] qtadc: [1×1 py.chipwhisperer.capture.scopes._qt.OpenADCQt] advancedSettings: [1×1 py.chipwhisperer.capture.scopes.cwhardware.ChipWhispererExtra.ChipWhispererExtra] trigger: [1×1 py.chipwhisperer.capture.scopes.cwhardware.ChipWhispererExtra.TriggerSettings] refreshTimer: [1×1 py.chipwhisperer.common.utils.timer.FakeQTimer] glitch: [1×1 py.chipwhisperer.capture.scopes.cwhardware.ChipWhispererGlitch.GlitchSettings] advancedSAD: [1×1 py.NoneType] clock: [1×1 py.chipwhisperer.capture.scopes._OpenADCInterface.ClockSettings] gain: [1×1 py.chipwhisperer.capture.scopes._OpenADCInterface.GainSettings] channels: [1×1 py.list] io: [1×1 py.chipwhisperer.capture.scopes.cwhardware.ChipWhispererExtra.GPIOSettings]

cwlite Device gain = mode = low gain = 45 db [cipher, trace] = measure_AES(cw, [22.50390625 adc = state = False basic_mode = rising_edge timeout = 2 offset = 1250 presamples = 0 samples = 3000 decimate = 1 trig_count = 173067711 clock = adc_src = clkgen_x4 adc_phase = 0 adc_freq = 29538471 adc_rate = 29538471 adc_locked = True freq_ctr = 0 freq_ctr_src = extclk clkgen_src = system extclk_freq = 10000000 clkgen_mul = 2 3 4 5 6 7 8 9 clkgen_div = 26 clkgen_freq = 7384615 clkgen_locked = True trigger = triggers = tio4 module = basic io = tio1 = serial_rx tio2 = serial_tx tio3 = high_z tio4 = high_z pdid = high_z pdic = high_z nrst = high_z glitch_hp = False glitch_lp = False extclk_src = hs1 hs2 = clkgen target_pwr = True glitch = clk_src = target width = 10 11 12 13 14 15],[.15625 width_fine = 0 1 2 3 4 5 6 7 8 9 offset = 10 11 12 13 14 15].15625 offset_fine = 0 trigger_src = manual arm_timing = after_scope ext_offset = 0 repeat = 1 output = clock_xor</pre>So to change the offset we set earlier with the matlab function we could do this:<pre> >> scope.adc.offset = int64(1500);</pre>The <code>int64()</code> function is needed so matlab does not pass a string through to the python function. We can see that the value has now changed by running:<pre> >> scope.adc.offset</pre>with this result:<pre>ans =

You can plot this power trace with 1500</pre><b>Note:it is good practice to check what type the attribute of the scope and target objects is, so you can assign the correct type using MATALB's int64()...etc functions.</b>

=== Manual 4.0 API Usage ===To import the chipwhisperer python module into MATLAB run<pre> plot>> cw = py.importlib.import_module(trace'chipwhisperer')</pre>This will work as long as you have the <code>chipwhisperer</code> module on your python path or system path. You can actually interact directly with the 'cw' as in Python, just as you would after running <code> import chipwhisperer as cw </code> in Python. So you can initialize a scope and a target:<syntaxhighlight lang=matlab> >> scope = cw.scope() >> target = cw.target(scope)</syntaxhighlight>Do some fun things with your chipwhisperer tool, like follow a wiki tutorial (you will just have to implement the examples with MATLAB instead), and close the connection when you are done:<syntaxhighlight lang=matlab> >> scope.dis() >> target.dis()</syntaxhighlight>

You can run a number of measure_AESBy default the CW-Lite starts recording at 1250 samples after the trigger (1250 / 4 = 312.5 target device clock cyles) calls with the same cw object without running cwconnect, and records for 3000 samples (3000 / 4 = 750 target device clock cycles) again. Note if you want to reconnectThese are suitable for the example AES in C, but you will first may need to run cw.disconnect() to close reduce the USB connectionoffset if running AES in assembly for example.

If you receive 'device in use' error messages, this is likely the problem. You can also simply unplug/replug the USB connection to forceThe ChipWhisperer-close any existing connectionsLite has a maximum capture length of about 24000 samples. The maximum offset is 4294967294.