F A Q

Known bugs in 3.0:

conversion of compound models yield compilation errors complaining about undefined "m.": fix available: contact CDW
bsim versions 3v31 and 3v32 do not run properly after starting ProMOST from Cadence: fix available: contact CDW
BSIM model files created in ProMOST 2.2 or older do not react on changes in W and/or L in ProMOST 3.0 and newer. This is due to an incompatibility introduced with extra functionality. Fix available: the most easy solution is to comment out the lines reading clearArray(); copyFromArray(); in the init() function in the process file and to recompile the files.
It is not possible to use an uninitialized schematic and let ProMOST
determine the transistor parameters (L, W, mult and fold) from scratch
because the parameter match is not done in this case. Just set some
(dummy) values to these parameters in the Cadence schematic first, so
that ProMOST can recognize them. will be fixed in version 3.1
The PBconverter is not able to convert process blocks containing Spectre
binning group selection. These processes use the binning parameters
WMIN, LMIN, WMAX, LMAX.
The PBconverter is not able to convert process blocks containing the new
Pstar syntax for instantiation of the components, with a space between the
model name and the instance name. This new syntax was introduced in
Pstar 5.2.
Currently most Pstar process blocks use the old syntax. For more
information, see the Pstar user manual or the Pstar 5.2 release notes.
Process blocks with a strong hierarchical structure may require manual
preprocessing before they can be successfully converted by the PBconverter.
This required preprocessing typically reduces the number of instances,
and hence the parsing loop count.

(not so) Frequently Asked Questions

1. Question, installation related:

After installing the JDK and ProMOST, running ProMOST gives error messages like

Oct 14, 2003 1:57:23 PM java.util.prefs.FileSystemPreferences$3 run WARNING: Could not create system preferences directory. System preferences are unusable.
....
found & linked process: B125PCb1 SC/Nym 2003
....
Oct 14, 2003 1:58:45 PM java.util.prefs.FileSystemPreferences checkLockFile0ErrorCode
WARNING: Could not lock System prefs. Unix error code 1956620564.
...

Answer:
Reason: It's caused by the JDK1.4 Preferences API, used to manage system-wide and per-user preferences. On Windows, the implementation uses the Windows Registry; on Unix/Linux, it uses the file system. The per-user prefs are kept near your home directory; the system-wide prefs are kept in the JDK installation. Of course, you can't write there unless you're root (or whoever owns the JDK installation). The JDK is not finding the system prefs directory in the installation and is trying to create it - an installation bug. Annoying, but not harmful.

Solution: To fix this, log on as root, and run any Java program (e.g. ProMOST 1.2). The SDK will indicate that it has created the directory and the permissions are set to work for any user. There are system preferences and user preferences. Only root will be allowed to change the system preferences, but anyone can read them.

[user]$ su
Password:

[root]# promost
31.feb.2003 20:21:22 java.util.prefs.FileSystemPreferences$3 run
INFO: Created system preferences directory in /etc/.java/.systemPrefs
...

Work around:
You can start the 1.2.1-a version of ProMOST. This however has less performance and a simplified GUI.

2. Question, installation related:

ProMOST on Linux does not work properly and is giving errors about missing Ksh.
Answer:
On your Linux system no Ksh is installed while the ProMOST scripts require the Ksh. You should install e.g. the public domain ksh pdksh.rpm on your system first. This rpm is usually provided with your Linux installation software.

3. Question, hardware related:

ProMOST may be very slow and eventually hang up.

Answer:
Reason: It's caused by insufficient memory. If ProMOST is run on low memory JAVA tries to free memory all the time, which is time-consuming and hence slow. If JAVA fails to free sufficient memory the program is halted. The amount of required memory depends heavily on the processes loaded into ProMOST and on the add-ins and wizards that are started. This problem usually occurs only on terminals.

Solution:
Add memory to your system. The memory footprint depends on the loaded processes, and on the running wizards and add-ins. Processes that show up in the process- selection box in ProMOST are loaded into memory. Depending on the complexity of the process-data files the memory requirement of a single process-data file typically range from 5kB to 5MB. The wizards and add-ins are loaded into memory only after starting them, to decrease the default memory requirement. Especially the PBconverter can consume up to 80MB when converting large process-data files.

Work around:
You can decrease the required memory load by only loading the processes you need, and by not-running wizards and add-ins. In that case you can get away with roughly 5MB free memory. You can check this in the System info tab in ProMOST.

4. Question, software related:

ProMOST does not start (under j2sdk 1.5) with an error log like:

Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.
...
Answer:
Reason:
On some machines there's insufficient memory to start JAVA 1.5 in its default installation settings. This is easy to verify by typing e.g. "java -version" which should report the installed JAVA version, but returns the specified error.
Computers with insufficient memeory for the default settings of JAVA 1.5 typically are log-in servers. Compute servers usually have sufficient memory.

Solution:
ProMOST uses the PROMOST_JRE environment variable to start JAVA. By default "PROMOST_JRE=java". If the specified error occurs you should start JAVA with a limited amount of memory by setting the PROMOST_JRE environment variable (e.g. in the ".profile" file) that limits the memory allocated for JAVA as e.g.

export PROMOST_JRE="java -Xmx256m"

5. Question, ProMOST 1.4 specific:

In ProMOST 1.4 some older process data sets do not properly scale W and L

Answer:
Reason: In ProMOST 1.4 some the W and L definitions are explicitly included in mos903 parameter sets, whereas up to the 1.3 version a different way of defining the W and L was used. This new way overrules the W and L definitions in older parameter sets, effectively resulting in using the default settings in mos903. This change is done to fully comply with the Pstar implementation of mos903, but may result in problems when using old parameter sets.

Solution:
The easiest solution is to re-convert the process data using the PBconverter.