22.214.171.124 Quantity Definition
All quantity types are described by a single structure.
An instance of this structure describes a single quantity and includes:
- The quantity and class identifier (see
- The scope of the quantity.
- A pointer to the corresponding device structure as well as the number of
the segment or boundary in case of a segment or boundary quantity,
- A description and a name for output and debugging purposes.
- A pointer to the corresponding properties structure (see
- Some additional information to communicate with the PIF-Libraries.
- The grid the quantity is defined on. It is used only in case of segment
or boundary quantities.
- The values (see Section 126.96.36.199).
- Maximum and minimum values define the range of reasonable values for the
quantity. This information is used during the Newton iteration to ensure
that, for instance, the temperature stays positive.
- For unit handling a lot of information is needed. This information is,
however, not stored within the quantity structure. During the initialization
phase when quantities are read from the input libraries they are scaled to
the internal unit associated with the unit class of the actual quantity type
(see Section 188.8.131.52). The scaling factor is implicitly
given by the internal unit associated to the unit class of the quantity type.
- Information is stored which depends on the quantity type, e.g., the
charge state of carrier quantities or the impurity number and the doping
material for impurity quantities.
- Each quantity allows to store so called old values. Old values
are written after each successful iteration. In case of a unsuccessful
iteration, the old values which are the result of the previous iteration can
be loaded. Additionally, update values and the residuum
values can be stored to monitor the progress of the Newton iteration
Fig. 3.5 shows the quantity structure and the important cross
references to the quantity type and the quantity values.
The quantity structure.