2-Parse Import for Managed Data
Introduction
Data may be imported into LakerTM Custom Layout via several methods: Stream, EDIF, CDL In, Laker-AMS, or by Expand Schematic. When importing data into an environment under Data Management (DM) control, cells must be checked out in order to be modified.
Import Scheme Prior to Laker 3.2v4p3
In Laker releases prior to 3.2v4p3, an entire design would be checked out prior to an import even if the cells were not present in the data to be imported. Each cell would be parsed and imported one by one. If a cell that was checked out or "locked" by another user was encountered, the import would fail and thus cease. This method was undesirable as the import would only be successful if each and every cell in the design was available for checkout without checking to see if the cell was in the import data. An import could fail on a "locked" cell that it was not even trying to import.
New Import Scheme for Laker 3.2v4p3
Laker 3.2v4p3 has a new 2-parse scheme for importing designs. The import is divided into 2 parts: Import and Expand. Import generates the schematic view and Expand generates the logic view. A list of the cells contained in the import data is generated. The cells in the design under DM are checked out based on the list generated. The process is as follows:
1. When executing "Import Stream", "Import EDIF", "Import CDL In", Import Laker-AMS", or "Expand Schematic", Laker will display a question box for the user to select the check out and check in scheme. When "Check out Cell View" and "Check in Cell View" are selected, the cells will be checked out, overwritten and checked back in.
Figure 1: Check Out and Check In Selection
2. A list of all "Library/Cell/Views" in the data to be imported is generated. This list will contain the cellviews that will be changed or overwritten during the import and will need to be checked out.
3. Laker issues the LDM commands to check out these cellviews. If a cellview is "locked" by another user, a Question box will be displayed requesting whether to continue or not. There are 3 options:
a. "Yes, Continue" - Laker will try to checkout the locked designs again and refresh the list of locked designs if any remain.
b. "No, Keep Locked" - The import will cease.
c. "No, Cancel Checkout" - All checkouts will be cancelled and the import will cease.
Figure 2: Question Box Controlling the Import
4. After the import is complete, the overwritten cellviews will be checked back in. If a cellview was checked out but not by the import process, it will not be checked back in. A list of cells that were created or overwritten is generated and contained in a file called "importCellList.log".
Summary
The 2-parse scheme implemented in Laker3.2v4p3 has improved the importing of data. Users are presented with a list of "locked" cells to unlock before importing new data. When the cells are unlocked the import may be continued. With the previous scheme, the import would cease when a locked cell was encountered and the user would have to unlock the cell and start over.
