Orientations
SRAM22 supports four placements: R90, R270, and their mirrored variants. Use these quarter-turn orientations in your integration flow.
pin edge origin corner orientation marker
| Placement | DEF code | Transformation in the original Cartesian frame |
|---|---|---|
| R90 | W | Rotate 90° counterclockwise |
| R270 | E | Rotate 270° counterclockwise |
| R90 + mirror | FW | Reflect across the original X axis, then rotate 90° counterclockwise |
| R270 + mirror | FE | Reflect across the original X axis, then rotate 270° counterclockwise |
The generated LEF declares SYMMETRY X Y R90. This permits a broader set of
candidate orientations, including N/R0 and S/R180: it does not encode the
project's four-orientation restriction. Explicitly constrain or check placements
in your integration flow. See the
LEF/DEF symmetry reference.
Signal pins are on met1 along the bottom edge in the generated frame. After a quarter turn that edge is vertical; the met2 power geometry rotates as well. Plan routing access and power connections using the transformed LEF geometry.
OpenROAD
With an initialized design:
place_inst -name u_mem -origin {120.0 80.0} -orientation R90 -status FIRM
Coordinates are in microns. -origin positions the transformed cell origin;
-location instead positions its bounding box. Check the
API for your OpenROAD version.
For Innovus, use the placement command or GUI in your flow's documented UI/version to apply one of the four transforms and fix the instance. Verify the resulting orientation and pin access in the placed database. See the OpenROAD and Cadence integration outlines.