Electric has a number of placement tools that can rearrange a circuit so that routing is easier. The tools can handle schematic or layout cells.

To run placement, use the Floorplan and Place Current Cell command (in menu Tools / Placement). This selects an appropriate placement algorithm to run.

For more precise control over placement, you can select a particular algorithm in the Placement Preferences (in menu File / Preferences..., "Tools" section, "Placement" tab) and then use the Place Current Cell with Preferred Algorithm command. The Placement Preferences not only selects the algorithm, but has parameters for controlling its operation.

Figure 9.26

These are the possible placement algorithms:

AlgorithmPlacerNotes
Force
Directed
#1Gives good results quickly (seconds). Additional time and threads does not improve results
#2Recommended for highly-symmetric cell layouts (pads, memory), but may be unstable
row/colUseful for fixed-pitch cells
Genetic#1 / #2Needs long runtime. Additional threads do not help
Simulated
Annealing
#1Not recommended for use
#2Has best overall results. Recommended runtime: 5 minutes
row/colUseful for fixed-pitch cells
Bottom-up partitionUsed to break large circuits into subproblems
Bottom-up placementFast and good quality for placing random-sized nodes
Min-cutSimple placer that does not use multiple threads
Simple and RandomPlaces linearly/randomly: not recommended