1 / 7

# CSE 144 Project Part 3 - PowerPoint PPT Presentation

CSE 144 Project Part 3. Overview. Goal: Implement a routing tool for standard cell design. Routing tool: Starts with the placement results Specifies positions of wires that connect pins. Routing Model. Regular-net routing Regular nets: wires within each channel

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about ' CSE 144 Project Part 3' - stephen-maldonado

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### CSE 144 ProjectPart 3

Goal: Implement a routing tool for standard cell design

Routing tool:

• Starts with the placement results

• Specifies positions of wires that connect pins

• Regular-net routing

• Regular nets: wires within each channel

• Fabrication model:2-layer VH model

• Feed-through routing

• Feed-throughs: wires crossing multiple channels

• Fabrication model

• Separate (the third) metal layer for vertical wires

• Horizontal wires share the same layer with regular nets

• Goal: Specify the assignment of horizontal feed-through wires to the channels

• Model each channel as a big track

• Problem solved using channel routing algorithm

• Pin locations may NOT necessarily be at the edges of the big channel

• Goal: Specify the routing configuration within each channel

• A typical channel routing problem

• Routing process needs to take into account the feed-through wires

• Vertical feed-through wires:

• Routed in a separate layer

• No contributions to horizontal/vertical constraints

• Horizontal feed-through wires:

• Routed in the same layer with horizontal regular wires

• Contribute to horizontal constraints

• No contribution to vertical constraints due to the absence of pins

• Both stages modeled as channel routing problem --- the Yoshimura-Kuh algorithm is used

• Exception case: loops in vertical constraints

• Solution: output a message indicating the detection of the loop, and immediately proceed to the routing of the next channel

• In feed-through routing:

• Possible exception case:fixed channel (big track) quantity --- might be insufficient for fulfilling horizontal&vertical constraints of feed-throughs

• Solution: proceed to regular-net routing immediately, and ignore feed-through wires in regular-net routing phase

Format

Net i : (PinPosition1, PinPosition2,...) [LeftmostPosition, RightmostPosition] TrackNumber