NET(5) File Formats Manual NET(5)
NAME
net - format of .net files read/written by Magic's netlist editor
DESCRIPTION
Netlist files are read and written by Magic's netlist editor in a very simple ASCII format. The first line contains the characters
`` Netlist File'' (the leading blank is important). After that comes a blank line and then the descriptions of one or more nets. Each
net contains one or more lines, where each line contains a single terminal name. The nets are separated by blank lines. Any line that is
blank or whose first character is blank is considered to be a separator line and the rest of its contents are ignored.
Each terminal name is a path, much like a file path name in Unix. It consists of one or more fields separated by slashes. The last field
in the path is the name of a label in a cell. The other fields (if any), are cell instance identifiers that form a path from the edit cell
down to the label. The first instance identifier must name a subcell of the edit cell, the second must be a subcell of the first, and so
on.
Instance identifiers are unique within their parent cells, so a terminal path selects a unique cell to contain the label. However, the
same label may appear multiple times within its cell. When this occurs, Magic assumes that the identical labels identify electrically
equivalent terminals; it will choose the closest of them when routing to that terminal. Further, after connecting to one of these termi-
nals Magic may take advantage of the internal wiring connecting them together and route through a cell to complete the net's wiring.
An example netlist file follows below. It contains three distinct nets.
----------------------------------------
Netlist File
alu/bit_1/cout
alu/bit_2/cin
regcell[21,2]/output
latch[2]/input
This line starts with a blank, so it's a separator.
opcode_pla/out6
shifter/drivers/shift2
----------------------------------------
SEE ALSO
magic(1)
4th Berkeley Distribution NET(5)