


LDMCDATA(3ICD)					   LDMCDATA(3ICD)



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     ldmcdata - LDMC technology data

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     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 _m_a_s_k_d_a_t_a (3ICD) file in the ICD process library.
     Short mask names and design rules are obtained from the
     _l_d_m_c_d_a_t_a file in the ICD process library, the format of
     which is described below.

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     The _l_d_m_c_d_a_t_a file contains one line per mask, but not all
     masks need to be present.	In fact, it typically only con-
     tains 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.

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     As an example, here is the _l_d_m_c_d_a_t_a 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.





		   The Nelsis IC Design System			1






LDMCDATA(3ICD)					   LDMCDATA(3ICD)



FFFFIIIILLLLEEEESSSS
     IIIICCCCDDDDPPPPAAAATTTTHHHH/lib/process/_p_r_o_c_e_s_s/maskdata
     IIIICCCCDDDDPPPPAAAATTTTHHHH/lib/process/_p_r_o_c_e_s_s/ldmcdata

SSSSEEEEEEEE AAAALLLLSSSSOOOO
     maskdata(3ICD), ll_init(5ICD), ll_process(5ICD).

















































2		   The Nelsis IC Design System



