connection to a net that has been decomposed into a resistor array
cannot be found. This indicates some fundamental error in the way
extresist works. However, it should not be producing an invalid
and unsimulatable netlist. Instead, it makes an arbitrary connection
from the device terminal to the resistor array and adds an entry in
the output netlist (.res.ext file). This results in a poor
representation of the resistor network to that terminal, but an
otherwise simulatable netlist. A warning is issued to note that an
arbitrary connection has been made. This is most typically a
"garbage in, garbage out" situation in which insufficient information
exists in a layout to inform magic on which direction current is
traveling through a net. However, it should be possible to rewrite
the extresist code so that magic makes somewhat informed decisions
about current paths and produces a halfway decent representation of
the actual net, instead of just giving up on the detailed extraction.
Looks to be used as integer bitmask which is flagged by compiler warning
as dubious, when using compiler provided type 'bool' from stdbool.h
in C99 instead of unsigned char type.
C29 bool type compatibility
a method that failed to work on devices with complex shapes on the
device recognition layer, such as snake-geometry resistors. (2)
The use of contact type "xpc" in the sky130 tech file as its own
contact residue caused the contact tracing in extresist to fail.
I opted to keep the unorthodox contact description in the tech
file and wrote an extension to a routine in extresist to handle
the case.
natural sort instead of ASCII-based sorting, so that ports that
are numbered arrays will be indexed properly by count. Also:
Modified the "extresist" handling of substrate to draw the default
substrate type over the entire cell area (less areas of nwell or
other conflicting type). This allows extresist to extract the
entire substrate as a resistive network. The result is ugly and
may warrant some aggressive network simplification, but it should
at least be realistic.
This commit makes the code (mostly) C99-compatible, enabling to compile
it without the -Wno-error=implicit-function-declaration flag. This
way, Magic becomes usable on arm64 architectures, specifically on Apple
computers with M1/M2 SoC.
solution; it would be much better to make the value adjustible, but
the array of tiles sized to LAYERS_PER_CONTACT is a Region structure,
and the routine that frees the Region structures does not have a way
to call a routine to take additional measures like free'ing a sub-
structure of the Region. A proper solution will require some work.
this appears to work correctly but does not yet handle the implicit
substrate (space as substrate) or "virtually" isolated substrate regions
(which need to be removed for full parasitic extraction).
support of devices with terminals on different plances, such as
capacitors, diodes, and bipolar transistors. Output now appears
to give meaningful results for flattened layouts, although
numerous issues remain for hierarchical layouts.
the last commit, unfortunately. Thanks to Matt Guthaus for alerting me
to this. Also updated parts of the extresist code that remove the
dependence on ResConDCS; this is a minor update and should not affect
the operation of extresist. It is preparatory to doing more work to
support additional device types like capacitors, bipolars, and diodes.
types and substrate connections. This is an intermediate step to
switching from a sim file format to an ext file format for input,
but resolves the worst issues of having the sim file not recognize
the devices or the substrate nodes. Implemented by using the sim
subcircuit format introduced in IRSIM with the "user subcircuit"
package. Implementation unfinished (work in progress).
a long-standing error (introduced with the "extresist geometry"
option) that can cause nets not to be extracted (due to the first
record not having extraction data, which was itself a long-standing
error in the code but which was not fixed correctly); (2) handle
"device mosfet" type transistors (previously only handled the old
"fet" type extraction devices); and (3) correct for the res.ext
file having a different scalefactor relative to the .ext file. The
latter item was solved by forcing all input to scale like
ExtCurStyle->exts_unitsPerLambda, locally correcting all input as
needed. Note that extresist still needs to handle other extraction
devices (e.g., resistors and capacitors) but those will require
additional handling in the routines which analyze the current path
to determine how to break up wires into paths.
simple FET device in extresist. Also: Extended the bloat-all CIF operator
again, allowing the trigger layer for the bloat operation to include both
CIF layers and magic layers (previously only magic layers were supported).
This extension is possible due to the previous extension allowing the
trigger layer and bloating layers to be on separate planes. This operator
extension is useful for tagging geometry that is in the proximity of, but
not overlapping, geometry on another plane.
Darryl L. Miles
Tim Edwards
Alessandro De Laurenzis