Conference cadsys::spice

280.0. "SPICE2G5 Version 4.9 Release Notes " by CADSYS::HALL (Dale) Tue Apr 29 1997 17:49

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    TO:  SPICE Users                  DATE:  April 28, 1997
                                      FROM:  Dale Hall
                                      DEPT:  DS/ABS/CAD&Test
                                      DTN:   225-5142
                                      LOC/MAIL STOP:  HLO2-2/B10

    SUBJ:  SPICE2G5 Version 4.9 Release Notice


    On April 28, 1997 the latest version of SPICE for both VAX and AXP 
    platforms became available.  

    Please note that this is the last planned release of SPICE for the VAX
    platform.

    There are no updates to the SPICE manual for this release.  Manuals are
    available and can be picked up from the documentation shelves at
    HLO2-2/G11.  If you do not work in HLO, a PostScript file may be copied
    from 

                   CADSYS::CAD$DOC:SPICE_USERS_GUIDE.PS


    Contact your system manager to have SPICE installed on your system.
    The installation kit may be found in:

                   CADSYS::CAD$KITS:SPICE049.A

    To install this kit, you may use the following command:

       $ @SYS$UPDATE:VMSINSTAL SPICE049 CADSYS::CAD$KITS:

           or

       $ COPY CADSYS::CAD$KITS:SPICE049.A local-area
       $ @SYS$UPDATE:VMSINSTAL SPICE049 local-area


    The installation kit will place this release memo,
    spice049.release_notes, in the SYS$HELP area where VMS keeps release
    notes for all installed software.  A copy will also be placed in
    CAD$ROOT:[SLED.NEW].


                           NOTE

           Please note that this SPICE release requires 
           OpenVMS VAX V6.1 and OpenVMS AXP V6.1 or later. 


    The logical 'SPICE$NODE' (defined by the installation kit) should be
    used to address the SPICE notes conference (which is located at
    SPICE$NODE::SPICE) and the SPICE mail account (SPICE$NODE::SPICE).


    Changes since V4.8 are:

    1. A change in the handling of writing the GRAPES file makes large 
    runs (with GRAPES file being written) noticeably faster.

    2. A bug in the run time library routine spice$alloc_time_mem() was
    fixed.  This bug was causing access violations in some runs.

    3. There was a bug in diode handling that could cause a crash when "UIC"
    was specified on the .TRAN statement.

    4. There was a problem with very large circuits (greater than 40,000 nodes)
    that caused SPICE to abort with a "pivot too small" error message.  This
    has been fixed.

    5.  There was a bug in the reporting of elapsed time at the end
    of the output file and in the log file.  If the job took longer than 24
    hours, then number of days was not printed.  For example,

      CPU             ELAPSED                 PAGE     DIRECT    BUFFERED
      TIME             TIME                  FAULTS     I/O        I/O        

    128: 7:45.63       8:50:21.61          5197929      96640     10131

    This has been corrected.  The above statistics will now look like this:     

    128: 7:45.63       5 8:50:21.61        5197929      96640     10131

    For a job that takes less than 24 hours, "0" elapsed days are reported:

      12:53:30.67      0 13:45:51.30          44614     104872     10496

    
    6. The version string that appears in the output file and the log file:

    *******24-APR-97 ***  SPICE (2G5)  V04.9   24Apr97  ***15:35:52********

    now includes "Big", "Huge", or "Mongo" if one of the memory-extended
    versions of SPICE was used:

    *****24-APR-97 ***  Big SPICE (2G5)  V04.9   24Apr97  ***15:42:43******


    7. A new MOS model, MOS11, has been introduced into this version of
    SPICE.  The model is briefly described below.  Further details on its
    development can be found in references 1 and 2, and an initial application 
    to CMOS7 is described in reference 3.  Questions on MOS11 should be 
    directed to Marden Seavey at DTN 225-7216.

    The MOS11 model was originally developed to eliminate the abrupt changes
    in slope and poor fits which can occur when using MOS10 to simulate the 
    device capacitances.  In particular, the poor fits and abrupt changes 
    occur in the transition regions from accumulation and strong inversion
    to the weak inversion region.  The MOS10 model uses an empirical smoothing
    function to connect the strong and weak inversion regions, and this may
    not always simulate the derivatives (i.e., capacitances) correctly, and
    can cause inaccurate curve shapes and abrupt changes as the gate voltage
    is swept.

    A more physical approach for treating the transitions to weak inversion 
    has been incorporated into MOS11, and this has made possible good fits to 
    capacitance data over the transition regions.  The approach is based on a
    full solution of the surface potential equation, and draws upon several 
    published works which show how to provide an accurate solution in less 
    than four iterations.  Also, many of the successful features of MOS10 
    have been retained in MOS11.  The new model is particularly applicable
    to analog and low voltage digital ciruits.  

    Other model enhancements of MOS11 include a Non-Quasi-Static (NQS) model 
    which is bias dependent.  This is important for long channel devices at
    high frequencies.  The new NQS feature is invoked by setting NQS=2 in
    the .OPTIONS control statement.  For a survey of the NQS approach in 
    MOS compact modeling and a discussion of the NQS part of the MOS11 
    model, see reference 4.  The MOS11 model also contains a complete 
    Silicon On Insulator (SOI) model.  See reference 5 for a description
    of recent SOI SPICE simulations using MOS11.

    For the initial test version of MOS11, the conductances and capacitances 
    were calculated numerically, which reduced the performance relative to
    MOS10.  The code in MOS11 has now been converted to analytical expressions
    for the first derivatives of quantities, and the conductances and 
    capacitances are now calculated from analytical expressions rather than 
    evaluated numerically.  This has produced a 24% improvement in performance 
    over the numerical version and the performance degradation compared to 
    MOS10 is now about 22%.

    8. A new model paramenter, REVNUM, has been introduced which is keyed to
    the present version of MOS11.  REVNUM is used only with LEVEL=11 which
    is the LEVEL parameter that calls MOS11.  The value of REVNUM which is
    now in use is 1.0.  Any other value for REVNUM will cause SPICE to 
    abort.  Also, SPICE will now abort if the REVNUM model parameter is
    omitted when LEVEL=11 is used.  If LEVEL has a value less than 11, the 
    REVNUM parameter is not used.

                                                            

1. R. Rios, "A Compact MOSFET Model for Low Supply Voltage and Analog
Circuit Simulations", Internal Digital Report, April 19, 1995.

2. R. Rios, "The MOS11 Model as Implemented in DECSPICE", Internal Digital
Report, August 27, 1996.

3. J. Clement, S. Oxx, M. Sur, M. Seavey, A. Bell, B. Zetterlund, "CMOS7-28
Rev. 0.0 Model Parameters for Review", Internal Digital Report, January 24,
1997.

4. F. Masszi, "The MOS Non-Quasi-Static (NQS) Compact Models in DECSpice
and in Berkeley Spice2e3", Internal Digital Report, October 14, 1996.

5. J. Sleight and M. Seavey, "SOI SPICE Simulations", Internal Digital 
Report, February 21, 1997.



    ====================================================================

    The installation kit now provides at least 4 separate SPICE executables
    (8 if the alternate architecture files are requested during
    installation).  In addition to the usual SPICE executable program there
    are two other versions provided which contain more memory.  They are not
    different in any way from "regular" SPICE; they simply allocate more
    memory. The "Big" version contains 10X the memory of regular SPICE, the 
    the "Huge" version 100X, and the "Mongo" version 250X.  The fact that
    Big, Huge, and Mongo SPICE have larger memory requirements impose
    certain constraints on both process quota parameters and SYSGEN
    parameters.  The minimum requirements are listed below.
 
              SPICE PGFLQUOTA / VIRTUALPAGECNT requirements
                           
                    Regular Big     Huge   Mongo
                    ------------------------------- 
    PGFLQUOTA        20K    125K    900K   2.3M ( PROCESS QUOTA parameter )

    VIRTUALPAGECNT   30K    150K    1M     2.5M( SYSGEN parameter )

    Regular SPICE is run in the same manner as before.  Typing "RUN
    SPICE$EXE" will cause SPICE to prompt for the input, output, and grapes
    files as before.  In order to run Big, Huge and MongoSPICE simply type

       RUN SPICE$EXE_BIG          - for BigSPICE
       RUN SPICE$EXE_HUGE         - for HugeSPICE
       RUN SPICE$EXE_MONGO        - for MongoSPICE

    The system knows what architecture type your machine is (VAX or AXP), so
    there is no need to specify this.

    There is one additional point that it is necessary to mention.  Should
    you wish to make use of the shareable image SPICE$SYSMODELS you must
    define the logical SPICE$SYSMODELS properly.  The possible options are
    listed below.

       DEFINE SPICE$SYSMODELS  SPICE$SYSMODELS_REG   (used with SPICE)
       DEFINE SPICE$SYSMODELS  SPICE$SYSMODELS_BIG   (used with BigSPICE)
       DEFINE SPICE$SYSMODELS  SPICE$SYSMODELS_HUGE  (used with HugeSPICE)
       DEFINE SPICE$SYSMODELS  SPICE$SYSMODELS_MONGO (used with MongoSPICE)

    Failure to do this can result in unpredictable results.