Table of Contents
The layout database is the place where all graphical data is stored. Toped uses its own database format called TDT. It deals purely with graphical data.There is no electrical or setup information stored there. A TDT file can be loaded as a target database or as a library. TELL defines several internal functions to deal with TDT databases.
- Toped libraries
The library in this context means layout blocks or IPs external to the current project which are supposed to be used "as is" and are not subject to change by any means. A typical example is a digital cell library delivered from the fab or other characterized standard cells used across multiply designs. Toped implements a concept of dynamically linked libraries.
- Libraries are loaded always in read only mode.
- Libraries can be loaded or unloaded "at will".
- Toped handles multiple libraries simultaneously, but only one target database.
- Library cells can be referenced from the target database as well as from other libraries.
- Cell references and cell definitions are linked by name only. Toped searches the current database first for a cell definition. If the cell is not found, Toped searches the following libraries in order of loading.
- The above principle is followed for both - target DB, and the libraries.
- If two libraries contain a cell definition with the same name, only one of them will be linked. The one defined in the library loaded first.
- If cell is not found, Toped indicates the cell reference as "undefined".
- Undefined references can be treated in the same way as defined ones. They can be moved, deleted and even copied.
- Every time a new library is loaded Toped relinks automatically the target database as well as all libraries that are already loaded.
- The above is true also when a library is unloaded.
Create a new empty design. This function defines the design name and more importantly the design data base units. By default the database is created with DBU = 1e-9 and UU = 1e-3. The above are the default GDSII units - (1 micron = 1000 DBU). Note that the value of the DBU defines indirectly the coordinate limits.
![[Tip]](images/tip.png) | newdesign … |
|---|---|
void newdesign ( void newdesign ( void newdesign ( void newdesign (
|
The second and fourth overloaded functions are defined for recovery purposes - Toped always uses those forms in the log file. time_created parameter is used later when the database is saved.
![[Warning]](images/warning.png) | Warning |
|---|---|
Use non-default DBU/UU settings with care esspecially when such a database is a source or target of any conversion to/from external formats. |
Load a TDT file and create TDT database (design) into memory. Toped handles only one target database at a time, so current design will be closed if the operation is successful. The loaded design becomes current.
| tdtread … |
|---|---|
void tdtread ( void tdtread (
|
The second overloaded function is used in the log files for recovery mode. It
reads the database only if the time_created
time stamp matches the corresponding
time stamp in the TDT file. time_updated
is important for a proper functionality of the recovery mode.
Example 2. tdtread
tdtread("/$TPD_LOCAL/tdt/toped_design.tdt");
tdtread("/home/guest_user/tpd_des.tdt",
"20-01-2006 01:09:53","21-05-2006 22:22:54");Load a TDT file as a library, relink and update the database into memory. Toped handles multiple libraries, so already loaded libraries will not be unloaded.
| void loadlib (file_name) |
|---|---|
|
Unload a library, relink and update the database into memory. The cells linked to this library will be relinked. If a cell definition doesn’t exists in the remaining libraries, the reference will be marked as "undefined"
| void unloadlib (lib_name) |
|---|---|
|
Save the current design to the disk in TDT format overwriting (updating) already existing file. The current design in memory is not changed or altered.
| tdtsave … |
|---|---|
void tdtsave() void tdtsave(
|
The second overloaded function is used in the log files for recovery mode. It
implements conditional save. The command is executed only if the time_created
time stamp matches the corresponding
time stamp of the database (or the existing
TDT file) and time_updated is newer than the corresponding one in the TDT file.
Save the design under a new name to the disk in TDT format. File with this name should not exist. The current design in memory is not changed or altered.
| void tdtsaveas (file_name) |
|---|---|
|
Convert TDT database to PostScript - The function translates the active layout database or part of it into PS format that can be used for printing.
| void psexport (cell_name, file_name) |
|---|---|
|
The objects which failed the validation checks, but are considered recoverable are stored away from the layout database in the GRC DB (Graphical rules check database). The GRC objects can’t be edited by any means. They can’t be even selected together with the validated objects. The sole purpose of the GRC DB is to store those objects temporary until an equivalent but valid object is created in the layout database.
The group of functions described below work with GRC DB.
Returns the list of cells of the active layout database which contain invalid layout objects.
| string list grcgetcells () |
|---|---|
- |
See the example in grcgetdata.
Returns the list of layers in the current active cell which contain invalid layout objects.
| int list grcgetlayers() |
|---|---|
- |
See the example in grcgetdata.
Returns the list of all GRC objects on a certain layer of the current active cell.
| auxdata list grcgetdata (layer) |
|---|---|
|
Example 8. grcgetdata
foreach(string name; grcgetcells())
{
echo(name);
opencell(name);
foreach(int layer; grcgetlayers())
{
echo(layer);
foreach(auxdata grcobject; grcgetdata(layer))
{
echo(grcobject);
}
grcrecoverdata(layer);
// alternatively ...
// grccleanlayer(layer);
}
}This function generates valid objects which are one to one layout equivalent of the GRC objects on certain layer of the current cell. The new objects are added to the corresponding layer of the active cell in the layout DB. As a side effect, the function also clears the recovered GRC objects.
| void grcrecoverdata (layer) |
|---|---|
|
See the example in grcgetdata.
Removes all GRC objects from a certain layer in the current active cell.
| void grccleanlayer (layer) |
|---|---|
|
See the example in grcgetdata.