Robert Dwyer Blog

Re: How to get the loading capacitance of a certain instance by encounter?

BobD — Wed, 22 May 2013 20:34:40 GMT

I believe total_capacitance does include input pin cap(s), wire capacitance does not.

Re: How to get the loading capacitance of a certain instance by encounter?

BobD — Wed, 22 May 2013 20:24:15 GMT

Here's an example:

report_property [get_nets [get_property [get_pins DTMF_INST/TDSP_CORE_INST/TDSP_CORE_GLUE_INST/i_962/Y] net_name]]

You can query individual values with get_property which should also accept specification of a -view:

get_property -view default_analysis_view_hold [get_nets [get_property [get_pins DTMF_INST/TDSP_CORE_INST/TDSP_CORE_GLUE_INST/i_962/Y] net_name]] wire_capacitance_max

Hope this helps,
Bob

Re: Getting instance orientation

BobD — Wed, 22 May 2013 12:07:28 GMT

Check out the dbGet database access mechanism. For example:

encounter 16> set inst [dbGet -p top.insts.name i1]

0x2aaab4ee11e8

encounter 17> dbGet $inst.orient

Here's a link to learn more: dbGet Quick Start

Hope this helps,
Bob

Re: ui_timingcon_file

BobD — Wed, 01 May 2013 19:33:01 GMT

If you want to include SDCs that target entities within the ILMs, but written from a top-level context, include them in the ,full.

If you want to write them in the context of the block-level, include them as part of the ILM definition itself.

Hope this makes sense.

-Bob

Re: ui_timingcon_file

BobD — Sun, 28 Apr 2013 13:16:48 GMT

This has tripped me up in the past as well. When you set these variables in the GUI it's more clear which is which.

The ",full" option is for ILMs. The rda_Input(ui_timingcon_file) is what you'd use if you're not using ILMs.

These notions are present when we go to using MMMC to configure the timing information as well.

Hope this helps,
Bob

Re: Place and route on SOC encounter

BobD — Mon, 18 Mar 2013 15:58:19 GMT

Check out the Floorplan Toolbox (Floorplan->Floorplan Toolbox...) - it provides ways to uniformly space/array selected hard macros.

Hope this helps,
Bob

Re: Instance Padding

BobD — Thu, 31 Jan 2013 14:36:55 GMT

Hmm. I'd suspect one of 2 things. Either the overall density is so high that the padding can't be honored. Or that some other placement setting is taking precedence over the instance padding. If the overall density is moderate (<95%) I'd try an experiment where I cleared out all non-default placement settings (setPlaceMode -reset), applied the instance padding, and ran a simple placeDesign. Let us know what you find! Sounds like an interesting puzzler.

PS You're always free to file a service request and if you can provide a testcase we'll be able to pin it down. Thanks for using the forums!

Re: decap-cells

BobD — Wed, 30 Jan 2013 14:39:41 GMT

They should be in both. I don't think there's a specific parameter that denotes decap cells - though I could be wrong.

If you have a hunch what their cell names might be, try searching for them in an active Encounter session like this:

encounter 1> dbGet head.allCells.name *DECAP*

Or look in the documentation provided by your library vendor.

Re: scripting or idea for PG strips and io pins

BobD — Wed, 30 Jan 2013 14:31:01 GMT

If you know where you want a specific pin to be placed, used "editPin -assign <x y> ...".

Let us know if you need help with other aspects of the scripting of this. I'm not sure I'm 100% catching what you're wanting to do.

Thanks!

Re: Instance Padding

BobD — Wed, 30 Jan 2013 14:24:11 GMT

By "not applied" do you mean you suspect the directive is being silently disregarded by the placer? Or the placer isn't honoring your request as judged by visual inspection?

If you suspect it's being silently disregarded check the value with "reportInstPad" to make sure the padding you requested is still there.

If you suspect the placer isn't honoring your constraints, consider a few things:

The value is specified in placement site units
The padding isn't guaranteed to occur on a specific side of a given instance
You can see what the unit size looks like visually compared to the cells by turning on placemen site visibility: All Colors->View Only->Row Site Pattern

I suspect that the value of "2" is just really small. Try a larger value, like one which equates to 50-100% the size of the instance you want padded.

Hope this helps,
Bob