How does EDI System identify spare cells in a post-mask ECO flow?

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How does EDI System identify spare cells in a post-mask ECO flow?

Spare cells should have a unique string in their instance name to identify them. Then the command specifySpareGate or ecoDesign -useSpareCells patternName is run to identify the spare instances. For example, if all spare cells have _spare_ in their name then they are identified using:

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specifySpareGate -inst *_spare_*

OR

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ecoDesign -spareCells *_spare_* ...

Note: if you are making manual ECO changes to a netlist and converting a spare cell to a logical instance, it's important to change the instance name. Otherwise, the instance may be identified as a spare cell if a future ECO is performed because it still has the spare cell instance name.

Example

The cell to be swapped is unplaced

image-20220307002842020

pre_buf: unplaced

spare_buf: placed

innovus 49> dbGet top.insts.name

spare_buf pre_buf UDriver USink

innovus 50> dbGet top.insts.

0x7f7b03ef60e0 0x7f7b03ef6150 0x7f7b03ef6000 0x7f7b03ef6070

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specifySpareGate -inst spare_*
ecoSwapSpareCell pre_buf spare_buf

image-20220307003059068

innovus 55> dbGet top.insts.name

pre_buf UDriver USink

innovus 56> dbGet top.insts.

0x7f7b03ef6150 0x7f7b03ef6000 0x7f7b03ef6070

innovus 57> dbGet top.insts.Pstatus

placed fixed fixed

Note: sparecell's pointer and name is swapped with the unplaced cell.

The cell to be swapped is placed

image-20220307004654614

innovus 62> dbGet top.insts.name

spare_buf pre_buf UDriver USink

innovus 63> dbGet top.insts.

0x7f7b03ef60e0 0x7f7b03ef6150 0x7f7b03ef6000 0x7f7b03ef6070

innovus 64> dbGet top.insts.pStatus

placed placed fixed fixed

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innovus 66> specifySpareGate -inst spare_*
Specifying instance [spare_buf] as spare gate.
Specified 1 instances as spare gate.
innovus 67> ecoSwapSpareCell pre_buf spare_buf

image-20220307005254488

innovus 68> dbGet top.insts.name

spare_buf pre_buf UDriver USink

innovus 69> dbGet top.insts.

0x7f7b03ef60e0 0x7f7b03ef6150 0x7f7b03ef6000 0x7f7b03ef6070

innovus 70> dbGet top.insts.pStatus

placed placed fixed fixed

Note: sparecell's pointer and name is swapped with the placed cell.

Error in "Innovus Text Command Reference 21.12"

ecoSwapSpareCell

If the cell to be swapped is unplaced, it is mapped to the spare cell. *instName* is deleted, and its connection is transferred to the spare cell. If the cell to be swapped is placed, it is swapped with the spare cell and is renamed to *instNameSuffix* if the -suffix option is used. If a suffix is not specified, the *instName* cell is renamed to *spareCellInstName*. The *instName* cell's connections are transferred to *spareCellInstName*. The input of *instName* is tielo, based on the global connection definition.

reference:

Answers to Top 10 Questions on Performing ECOs in EDI System

EE 582: Physical Design Automation of VLSI Circuits and Systems