10.06.2016 Views

eldo_user

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Eldo Netlist Setup<br />

Protection of Encrypted Libraries<br />

Creating the IP Access Library<br />

Installing a Protected Library<br />

List of Encryption Errors and Warnings<br />

Semi-Transparent Encryption<br />

Semi-transparent encryption enables an encrypted part of the circuit to behave as if it was<br />

protected by a .PROTECT/.UNPROTECT block.<br />

By default, non-semi-transparent encryption blocks are not printed in the output file nor<br />

accessible through various plotting and extracting functions of Eldo. However, commands and<br />

devices that are not encrypted but appear in a protected block are not printed in the output file,<br />

but it is still possible to plot or extract nodes and devices.<br />

Semi-transparent encryption avoids encrypted content from being printed in the output file, but<br />

enables that content to be plotted or extracted.<br />

• Semi-transparent encryption with the encrypt_<strong>eldo</strong> utility<br />

Specify encrypt_<strong>eldo</strong> command line argument -semi to activate semi-transparency for<br />

encrypted blocks generated from subcircuit definitions and .PROTECT/.UNPROTECT<br />

blocks.<br />

• Semi-transparent encrypted blocks<br />

An encrypted block in a circuit netlist appears as consecutive lines made of a heading %<br />

sign followed by a string of hexadecimal characters of an arbitrary length, for example:<br />

%886B59DED5CEB36FC3D6EE8D90E8048F<br />

%BB6460E7E01502C4F0D03A632D324F2D<br />

Eldo deciphers the block into a list of original text lines:<br />

.INCLUDE r.inc<br />

V1 0 1 10<br />

A semi-transparent encrypted block looks exactly like a normal encrypted block, but<br />

once deciphered, the first command is .SEMITRANSPARENT. If the command appears<br />

anywhere but at the beginning of the deciphered lines, it is discarded. For example, if an<br />

encrypted block is deciphered into the following original text lines, then these lines are<br />

handled as semi-transparently encrypted:<br />

.SEMITRANSPARENT<br />

.INCLUDE r.inc<br />

V1 0 1 10<br />

When encrypt_<strong>eldo</strong> command line argument -semi is specified, it produces encrypted<br />

blocks starting with the .SEMITRANSPARENT command (for encrypted blocks<br />

generated by subcircuit definitions and the .PROTECT/.UNPROTECT blocks).<br />

Eldo® User's Manual, 15.3 147

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!