1 Chip Assembly Using the Virtuoso Chip Assembly Router (vcar) Yet Another Tool... This is a tool you can use to connect large blocks that have been designed separately Like placed and routed blocks from SoC, or memories, or custom register files, etc. Also useful for wiring a fully-connected core to the pads Hand-placement, but automated wiring... Chapter 12 in CAD book2 Outline 1. Start with a schematic to define connectivity 2. Then generate a layout template into Virtuoso-XL 3. Place blocks by hand and adjust floorplan 4. Wire vdd and gnd by hand 5. Export to vcar for signal routing 6. Import back into Virtuoso for DRC, LVS, GDS Example Start with schematic that defines connectivity3 Generate layout from schematic Generate Layout Generate layout from schematic Generate Layout4 Drag to place floorplan Floorplan before routing5 Export to vcar Export to vcar6 Layout after routing Example of Core to Pad Routing7 Example Pins on Pad (layout) Core and Frame in Virtuoso-XL8 Make Vdd and Gnd connections After vcar routing9 Now generate gdsII (stream) The binary format that MOSIS wants Use export->stream Make sure to load stream4gds.map as the Layer Map File One Final Tweak If you’re fabbing, before you generate your final fab-read gdsII (stream) file... ...You need to add blocks of poly, M1, and M2 to meet the minimum density requirements Take open areas of your chip and add large blocks of those layers Remember to DRC and LVS to make sure you didn’t mess anything up!10 Example Chip (4tcu) Example Chip (2tcu)11 Example Chip
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