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Extract Spice netlist of Clock Tree with Parasitic RC and inserted buffers

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Full Member level 4
Oct 21, 2006
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Dear all
Is there any way to extract Clock tree netlist from a post placed and routed design?
I want to simulate Clock tree with its parasitic RC elements which has been extracted from the design and inserted buffers in HSPICE.
I am impatiently wait to any guidance.
Thanks in advance.

Primetime could do that with "write_spice_deck".
The command to generate a SPICE deck is the write_spice_deck command. Using the command requires a PrimeTime SI license. The command generates a SPICE netlist that includes the cells of a specified path or arc, together with the resistors, ground capacitors, and coupling capacitors to aggressor nets related to the nets in the path or arc. It also generates the stimuli to sensitize the victim path and aggressors according to the options specified in the write_spice_deck command.

Dear rca
I am familiar with Spice Deck Extraction with PrimeTime SI of a path. I simulated my design critical path with write_spice_deck output, a lot. But i could not extract the spice netlist of clock tree with write_spice_deck. I think i could not define a proper timing arc or timing path in write_spice_deck. Could you write a sample write_spice_deck which generates spice netlist of whole clock tree?
Thanks in Advance.

For PT -

If you add “-path full_clock_expanded” to the timing path used for write_spice_deck this should do it for you.

You can try StarRC also for this.. Please follow the below mention steps ..

1. Generate a StarRC-extracted parasitic file written in spef format that preferably contains only the critical nets of interest (selected net extraction).
a. Use the “NETS” command in the ‘starxt.cmd’ file:
i. Nets: <netA>
ii. Nets: <netB>
iii. Etc.
Note: selected net extraction requires use of the ‘StarXtract –clean’ command-line option, which demands the full cost of StarRC runtime.

2. Given any previous StarRC run (either full or selected net extraction) generate a SPICE format file from within the original run directory.
a. In ‘starxt.cmd’ file change:
b. No other command file changes should be made (do not change NUM_PARTS).
c. Use the –cleanN option, which completes much faster than a full StarRC run: ‘StarXtract –cleanN’.
d. Run StarRC on a single cpu, regardless of the setting of the command file entry ‘NUM_PARTS’
e. No other command file changes should be made (do not change NUM_PARTS).

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