Provided by: sch-rnd-core_0.9.3-1_amd64 
NAME
boxsym-rnd - boxsym description syntax
DESCRIPTION
A boxsym file specifies symbol attributes and pins (terminals) for a single box symbol or
for a set of inhomogenousely slotted box symbols. When slotted symbols are generated, one
symbol file is generated for each slot containing only the pins defined for the given slot
(file name suffixed with slot name) and a monolith symbol is generated (using the original
file name) with all pins in one large box.
Syntax
The boxsym syntax is a plain text, line based, hierarchical file format with a syntax
similar to tEDAx. Leading whitespace in lines are ignored. Empty lines and lines starting
with a hashmark (#) are ignored. The first word of a line is a command.
If the command is begin , the rest of the lines until the matching end line are read as a
nested level of hierarchy. The syntax allows "begin in begin" (nesting to any depth). The
second word of begin and end are the type of the nested subtree.
Commands issued outside of any begin-end blocks are said to be made in global scope.
Refdes
There can be only one refdes line, in global scope. The argument is a single word, the
refdes attribute. If no refdes is specified, the default refdes is used.
Attributes
Attributes are symbol attributes. Attributes specified in the global scope will be present
in every symbol generated from the file. Attributes specified for a slot will be present
in the slot's symbol and in the monolith symbol.
An attribute is defined in the following form:
attr key value
Key is a single word, value is anything up to the end of the line. This defintion creates
the attribute and places a dyntext+floater text object printing the value of the
attribute. If command is attr_both , the text object is created to print key=value. If
command is
attr_invis the attribute is still created but no text object is made.
Other global settings
A line starting with text_size_mult followed by a decimal number (greater than zero)
changes text pixel length allocation factor. Increasing values will allocate more pixels
to each text in length (text height is not affected).
Defining pins
Pins are defined using a pin subtree: begin pin pinname, then lines defining pin
properties and then an end pin. Pinname should be the textual, human readable name of the
pin (also used as an input for the optional devmap), not the physical pin number.
For example:
begin pin Vcc
num 14
loc top
end pin
begin pin B
num 2:5:10:13
loc left
dir in
invcirc
end pin
Within the pin block the num line specifies the physical footprint pin number; for a pin
participating in a slot this should be a colon separated list of pin number per slot.
The mandatory loc line specifies the location of the pin, the side of the box on which it
should be placed, one of: left, right, top or bottom.
If a dir line is present, extra "pin direction" graphics is drawn for the pin inside of
the box. Values are in or out
If invcirc is present, the pin will have a small circle near the box to indicate the pin
is inverted.
If label is present its value (anything written after "label") is printed within the box
next to the pin instead of the pin name.
Arranging pins
By default pins are listed per side (loc), tightly packed, in order of appearance in the
file from the start of the side. This can be changed using pinalign lines in global or
slot scope:
pinalign left center
will arrange left side pins on the center (vertically).
Defining a single box symbol
The simplest form of box symbols emit a single file that has a single large box with all
pins. The boxsym definition for such symbols contain the above described constructs and no
"begin slot" subtrees.
Defining inhomogenous slot symbol
In an multi-box, inhomogenous slot symbol there are different symbols representing
different sections of the component.
The typical example is an MCU which is split up into a couple of boxes: a few boxes per
port groups and another few per peripheral types. Each box represents a slot that appears
only once in the MCU.
Another typical example is logic ICs, e.g. 7400 implemented in two different slot symbols:
one for power (Vcc and gnd), presents once in the component, and one for a 3 pin gate,
same box used 4 times for 4 different slots.
An inhomogenous slot symbol does not have any pin in global scope, but defines one or more
"begin slot slotname" subtrees for all the different type of slots. If the same slot
appears multiple times in the component, it needs to be defined only once (and multiple
pin numbers assigned in pin definitions.)
EXAMPLE
Single box LDO
refdes U??
attr_invis sym-source sch-rnd default symbol lib
attr_invis sym-copyright (C) 2022 Tibor 'Igor2' Palinkas
attr_invis sym-license-dist GPLv2+
attr_invis sym-license-use Public Domain
pinalign bottom center
pinalign left center
pinalign right center
shape box
begin pin in
num 1
loc left
end pin
begin pin gnd
num 2
loc bottom
end pin
begin pin out
num 3
loc right
end pin
Inhomogenous slot 7400
refdes U??
pinalign right center
pinalign bottom center
pinalign top center
attr device 7400
begin slot power
shape box
begin pin Vcc
num 14
loc top
end pin
begin pin gnd
num 7
loc bottom
end pin
pinalign top center
pinalign bottom center
end slot
begin slot logic
attr device 7400
attr_both slot 1
begin pin A
num 1:4:9:12
loc left
dir in
end pin
begin pin B
num 2:5:10:13
loc left
dir in
end pin
begin pin Z
num 3:6:8:11
loc right
dir out
invcirc
end pin
pinalign left center
pinalign right center
end slot
SEE ALSO
boxsym-rnd(1)
2022-03-28 boxsym-rnd(5)