Assembler

A general 2-pass assembler with implementations of LC-2200 and LC3-2200a.

Requirements

The assembler runs on any version of Python 2.6+. An instruction set architecture definition file is required along with the assembler. In this repository, several sample ISA definitions have been provided (see below).

Sample Definitions

• LC-2200 (32-bit)
• LC3-2200a (32-bit)

Options

The assembler contains multiple options.

python assembler.py -h prints:

usage: Assembles generic ISA-defined assembly code into hex or binary.
       [-h] [-i ISA] [-v] [--hex] [-s SEPARATOR] [--sym] [--params PARAMS]
       asmfile

positional arguments:
  asmfile               the .s file to be assembled

optional arguments:
  -h, --help            show this help message and exit
  -i ISA, --isa ISA     define the Python ISA module to load [default: isa]
  -v, --verbose         enable verbose printing of assembler
  --hex, --logisim      assemble code into hexadecimal (Logisim-compatible)
  -s SEPARATOR, --separator SEPARATOR
                        the separator to use between instructions (accepts \s
                        for space and standard escape characters) [default:
                        \n]
  --sym, --symbols      output an additional file containing the assembled
                        program's symbol table
  --params PARAMS       custom parameters to pass to an architecture,
                        formatted as "key1=value1, key2=value2, key3=value3"

How to Use

Typical usage:

./assembler.py <assembly_file> -i <isa_definition>

Example usage with the lc2200.py definition:

./assembler.py assembly.s -i lc2200

To output assembled code in hexadecimal (compatible with Logisim images):

./assembler.py assembly.s -i lc2200 --logisim

To separate entries by a space:

./assembler.py assembly.s -i lc2200 --separator \s