+ This is a proposal at this stage - any detail may change any time +
+Sometimes a design is easier specified by text than drawing. Typical examples: +
+Non-graphical sheets are implemented in plugins and provide different +methods and syntax for specifying abstract components, abstract networks +and their relations. The cschem compiler can use this as an input on the same +level as a graphical sheet. That means, it can be an Nth sheet in +a multisheet project. For example draw the power and analog parts on graphical +sheets and have the 28 pin parallel bus connections to the CPU, ram, I/O chips +and connectors specified in one more more non-graphical sheet in the same +project. +
+Below are different methods and syntax to describe non-graphical sheets. + +
+tEDAx is very easy to parse, well specified, and is relatively easy to +read and write as human. +
+Here are a few small examples, all describing the same "7805 with 2 bypass +caps" circuit using different approaches: +
+These are not different sets of syntax, but they are all just different usage +and combination of the same few blocks that are all available. As a proper +declarative description, order of blocks or order of attributes/connections +within a block doesn't matter. +
+The verbose versions are perhaps more practical if there are a lot of attributes +to specify. The compact version is more practical for listing a lot of +connections and few attributes. +
+Another way of mixing different blocks is big32.tdx, +which is an imaginary CPU board with 2 SRAM chips, an I/O chip and an extension +port. It uses the verbose component description for the chips and capacitors, +also connects power and gnd there and then uses the compact, table-like +description for the address/data/control networks. It's also an example +of combining graphical and non-graphical sheets: U5 is a network of gates +that controls chip-select; it's better drawn for clarity. + + + + \ No newline at end of file Index: non-graphical/small1.tdx =================================================================== --- non-graphical/small1.tdx (nonexistent) +++ non-graphical/small1.tdx (revision 7098) @@ -0,0 +1,43 @@ +tEDAx v1 + +# Verbose, network based +# Advantage: no need to worry about escaping (e.g. spaces) +# Disadvantage: long, verbose files, harder to oversee + +# contains: attributes only in "key value" format +begin cschem_acomp U1 + footprint TO220 + device 7805 +end cschem_acomp + + +begin cschem_acomp C1 + footprint 1206 + device capacitor +end cschem_acomp + +begin cschem_acomp C2 + footprint 1206 + device capacitor +end cschem_acomp + +# contains: attributes in "key value" format; +# lines with first word being a dash represent a connection between +# this net and a component terminal (in component-name terminal-name +# format); terminals are created automatically +being cschem_anet gnd + - U1 2 + - C1 2 + - C2 2 + comment use poly +end cschem_anet + +being cschem_anet Vin + - U1 1 + - C1 1 +end cschem_anet + +being cschem_anet Vout + - U1 3 + - C2 1 +end cschem_anet Index: non-graphical/small2.tdx =================================================================== --- non-graphical/small2.tdx (nonexistent) +++ non-graphical/small2.tdx (revision 7098) @@ -0,0 +1,40 @@ +tEDAx v1 + + +# Verbose, component based +# Advantage: no need to worry about escaping (e.g. spaces); component-oriented +# view; useful if there's one large central component (e.g. fpga) +# Disadvantage: long, verbose files, harder to oversee + +# contains: attributes only in "key value" format +# if first word is -, make a connection from the named termina to +# the named network (networks and terminals are created automatically) +begin cschem_acomp U1 + footprint TO220 + device 7805 + - 1 Vin + - 2 gnd + - 3 Vout +end cschem_acomp + + +begin cschem_acomp C1 + footprint 1206 + device capacitor + - 1 Vin + - 2 gnd +end cschem_acomp + +begin cschem_acomp C2 + footprint 1206 + device capacitor + - 1 Vout + - 2 gnd +end cschem_acomp + +# specify net only if extra attributes are needed +being cschem_anet gnd + comment use poly +end cschem_anet + + Index: non-graphical/small21.tdx =================================================================== --- non-graphical/small21.tdx (nonexistent) +++ non-graphical/small21.tdx (revision 7098) @@ -0,0 +1,41 @@ +tEDAx v1 + +# Verbose, mixed network/component based +# +# This file combines small1.tdx and small2.tdx syntax, read those +# files for semantics +# +# Advantage: no need to worry about escaping (e.g. spaces) +# signals of a central component (e.g. fpga) specified at comp +# boring networks, like gnd, can be specified at the net +# Disadvantage: long, verbose files, harder to oversee + +# Components; Vin and Vout connections are specified from the components' +# point of view +begin cschem_acomp U1 + footprint TO220 + device 7805 + - 1 Vin + - 3 Vout +end cschem_acomp + + +begin cschem_acomp c1 + footprint 1206 + device capacitor + - 1 Vin +end cschem_acomp + +begin cschem_acomp c2 + footprint 1206 + device capacitor + - 1 Vout +end cschem_acomp + +# gnd is a large network, specified from the net's point of view +being cschem_anet gnd + - U1 2 + - C1 2 + - C2 2 + comment use poly +end cschem_anet Index: non-graphical/small3.tdx =================================================================== --- non-graphical/small3.tdx (nonexistent) +++ non-graphical/small3.tdx (revision 7098) @@ -0,0 +1,29 @@ +tEDAx v1 + +# Compact, combined list +# Advantage: brief file, almost like a table, easy to oversee +# Disadvantage: have to escape spaces; need to watch for line length limit +# when line gets longer than 510 characters, need to split +# (repeating the "comp name=..." or "conn name=..." part) + +# Each line starts with a comp, net or conn; they create a component, +# a network or make a connection respectively. First argument is always +# the name (unique identifier) of the given object. Multiple lines can have +# the same identifier, the content of those lines are merged. +# +# For comp and net lines, starting from the second argument fields are +# key=value pairs for setting attributes. +# +# For conn lines, starting from the second argument fields are +# comp-name=term-name; terminals are created automatically. + +begin cschem_acompact + comp U1 footprint=TO220 device=7805 + comp C1 footprint=1206 device=capacitor + comp C2 footprint=1206 device=capacitor + net gnd comment=use\ poly + conn Vin U1=1 C1=1 + conn gnd U1=2 C1=2 C2=2 + conn Vout U1=3 C2=1 +end cschem_acompact +