LDMCDATA(3ICD)

NAME
ldmcdata - LDMC technology data

DESCRIPTION
The LDMC procedural layout system has a limited but useful knowledge of technology and design rules. This knowledge is not built into the code, but is obtained from the design environment during initialization (see ll_init(5ICD)). This allows the system to be used for different technologies and even to write layout generators that are, to a certain extent, technology independent.

Layer names and general technology information is obtained from the maskdata (3ICD) file in the ICD process library. Short mask names and design rules are obtained from the ldmcdata file in the ICD process library, the format of which is described below.

FORMAT
The ldmcdata file contains one line per mask, but not all masks need to be present. In fact, it typically only contains information for the interconnect masks. Comments are surrounded by sharp (#) and newline. Each line has a number of fields, the first three specify mask name, mask id and minimum width. Then, a number of fields equal to the number of masks specified in the file give the separation between masks. For example, in the first line, the fourth field gives the minimum separation between two wires in the first mask, the fifth field between a wire in the first and a wire in the second mask, etc. More generally, the i+3-th field in line j gives the separation between mask i and j for 1 <= i,j <= number of masks. These fields are in fact one row of the (symmetrical) mask_sep matrix of the LDMC process descriptor, see ll_process(5ICD). If the separation is 0, the masks are allowed to overlap.

EXAMPLE
As an example, here is the ldmcdata file for a standard 4u nmos process for a value of lambda of 2u:

# Ldmc technology description for standard 4u nmos process
# name  id      width   sep
np      p       2       2 1 0
nd      d       2       1 2 0
nm      m       2       0 0 2

For example, we see that (1) the short name for mask np is 'p', (2) its minimum width is 2 lambda, (3) the minimum np-np separation is 2 lambda, (4) the minimum np-nd separation is 1 lambda, and (5) np and nm are allowed to overlap.

FILES
ICDPATH/lib/process/process/maskdata
ICDPATH/lib/process/process/ldmcdata

SEE ALSO
maskdata(3ICD), ll_init(5ICD), ll_process(5ICD).