Scrambler: Difference between revisions

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(Created page with "Category:Block Docs Category:Stub Docs This is the template for the "Page-per-block Docs". This first section should describe what the block...")
 
(Yeah there was a typo, now it's fixed. Sorry.)
 
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[[Category:Block Docs]]
[[Category:Block Docs]]
[[Category:Stub Docs]]
Scramble an input stream using an LFSR.
This is the template for the [[:Category:Block_Docs|"Page-per-block Docs"]].  This first section should describe what the block does and how to use it, using however many paragraphs necessary.  Note that the title of the wiki page should match the block's name in GRC, i.e. the one defined in the block's .grc file.  Look at the [[FFT]] Block for a good example.


As this is a basic template, it's also in the [[:Category:Stub_Docs|"Stub Docs category"]]. Please improve it.
This block works on the LSB only of the input data stream, i.e., on an "unpacked binary" stream, and produces the same format on its output.


== Parameters ==
== Parameters ==
(''R''): <span class="plainlinks">[https://wiki.gnuradio.org/index.php/GNURadioCompanion#Variable_Controls ''Run-time adjustable'']</span>


; Param 1 (''R'')
; Mask
: Description of parameter, provide any tips or recommended values.  Note that the name of the parameter above should match the param's label that shows up in grc (e.g. Sample Rate).
: Polynomial mask for LFSR


; Param 2
; Seed
: blah blah blah
: Initial shift register contents
 
; Length
: Shift register length


== Example Flowgraph ==
== Example Flowgraph ==


Insert description of flowgraph here, then show a screenshot of the flowgraph and the output if there is an interesting GUI.  Currently we have no standard method of uploading the actual flowgraph to the wiki or git repo, unfortunately.  The plan is to have an example flowgraph showing how the block might be used, for every block, and the flowgraphs will live in the git repo.
Insert description of flowgraph here, then show a screenshot of the flowgraph and the output if there is an interesting GUI.  Currently we have no standard method of uploading the actual flowgraph to the wiki or git repo, unfortunately.  The plan is to have an example flowgraph showing how the block might be used, for every block, and the flowgraphs will live in the git repo.
Here is a simple python-function to create the mask and length from the exponents of a polynomial:
  def make_mask(*exp):
      from functools import reduce
      return reduce(int.__xor__,map(lambda x:2**x,exp)),max(exp)-1
  mask,k = make_mask(5,3,0) # mask and length for p(x) = x^5 + x^3 + 1, a primitive polynomial in GF(2)


== Source Files ==
== Source Files ==

Latest revision as of 15:03, 27 November 2020

Scramble an input stream using an LFSR.

This block works on the LSB only of the input data stream, i.e., on an "unpacked binary" stream, and produces the same format on its output.

Parameters

Mask
Polynomial mask for LFSR
Seed
Initial shift register contents
Length
Shift register length

Example Flowgraph

Insert description of flowgraph here, then show a screenshot of the flowgraph and the output if there is an interesting GUI. Currently we have no standard method of uploading the actual flowgraph to the wiki or git repo, unfortunately. The plan is to have an example flowgraph showing how the block might be used, for every block, and the flowgraphs will live in the git repo.

Here is a simple python-function to create the mask and length from the exponents of a polynomial: 

 def make_mask(*exp):
     from functools import reduce
     return reduce(int.__xor__,map(lambda x:2**x,exp)),max(exp)-1
 mask,k = make_mask(5,3,0) # mask and length for p(x) = x^5 + x^3 + 1, a primitive polynomial in GF(2)

Source Files

C++ files
TODO
Header files
TODO
Public header files
TODO
Block definition
TODO
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