Routing Flow

Route Clock nets

↓

Route signal nets

↓

optimize trace topology

↓

Post route clock tree optimization

↓

all nets routed

↓

skew and timing ok? no→ Post route CTO
↓yes
Search and repair

Route clock nets:
To meet the specified insertion delay and skew it is necessary that clock nets be routed first, they can have the most direct-routing.
This also indicates to route the critical signals and buses in the design.


Route signal nets:
After the critical nets are routed the signal nets non-critical ca be routed.The process of routing is timing-driven.Routing of timing critical path is given highest priority in order to maintain the overall timing so that the route is as short as possible.Nets that are non-critical are routed around critical areas to provide more wiring area for critical nets.



Post route CTO:
Minor clock skew and timing violations may have been introduced by previous routing and optimization steps,which are fixed in this step.