DESCRIPTION

The lotrs is used to describe a logical transistor. It is mostly used to describe leaf cells in terms of transistors interconnections, and as a result of layout extractions. Since the only target technology is CMOS, only NMOS and PMOS transistors are used.

The declarations needed to work on lotrs are available in the header file "/labo/include/mlo.h".

The following C structure supports the description of the logical transistor :

typedef struct lotrs {
   struct lotrs     *NEXT; 
   struct locon     *DRAIN;
   struct locon     *GRID; 
   struct locon     *SOURCE;
   struct locon     *BULK;
   char             *TRNAME;
   long             X,Y;
   unsigned short   WIDTH, LENGTH;
   unsigned short   PS, PD;
   unsigned short   XS, XD;
   char             TYPE;
   struct ptype     *USER;
} lotrs_list;

NEXT

Pointer to the next lotrs of the list.

DRAIN

Pointer to the drain connector of the transistor. This connector is, of course unique. See locon(3) for details.

GRID

Pointer to the grid connector of the transistor. This connector is, of course unique. See locon(3) for details.

SOURCE

Pointer to the source connector of the transistor. This connector is, of course unique. See locon(3) for details.

BULK

Pointer to the bulk connector of the transistor. This connector is, of course unique. See locon(3) for details.

TRNAME

Transistor instance name

X, Y

Coordinates of the transistor in a layout. These informations have sens only if the transistor netlist is the result of a layout extraction. They are otherwise set to zero. These coordinates are given in micron times the scale factor SCALE_X, since the extracted view is technology dependant.

WIDTH, LENGTH

Respectivly width and length of the transistor grid.

PS, PD

Respectivly perimeter of the source and drain, in micron times the scale factor SCALE_X.

XS, XD

These values are needed to compute respectivly the source and drain areas. Let As be the source area in square microns, and Width be the transistor grid width in micron, then lotrs->XS = As / Width * SCALE_X

TYPE

Canal type of the transistor. Six legal values are available :

TRANSN

N type MOS transistor

TRANSP

P type MOS transistor

TRANSN_FAST

High speed N type MOS transistor

TRANSP_FAST

High speed P type MOS transistor

TRANSN_HVIO

Low Leakage N type MOS transistor

TRANSP_HVIO

Low Leakage P type MOS transistor

USER

Pointer to a ptype list, see ptype(3) for details, that is a general purpose pointer used to share informations on the transistor.

Remark :

In integrated techniques, NMOS transistor bulk for digital circuits is always set to ground, and PMOS transistor bulk for digital circuits is always set to positive supply.