https://github.com/amdzy/hackassembler

https://github.com/amdzy/hackassembler

Last synced: 3 months ago
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• Host: GitHub
• URL: https://github.com/amdzy/hackassembler
• Owner: amdzy
• Created: 2022-12-18T06:14:40.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2022-12-18T06:24:39.000Z (over 2 years ago)
• Last Synced: 2025-01-22T02:28:32.424Z (4 months ago)
• Language: Assembly
• Size: 138 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# HackAssembler

An assembler for the hack language written in java     

The program takes as an input an assembly file and outputs a hack file     


![assembler](image/assembler.png)

* **Symbols**

    * *Label symbols* (In the program above *LOOP* and *END* are label symbols) are used to mark the memory location of the next instruction in the program. Label symbols are used for *control flow* in the program.

    * *Variable symbols* (In the program above *i* and *sum* are variable symbols) are treated as *variable*. Variables are mapped to consecutive memory locations.

    

* **Symbols table**: Since Hack instructions can contain symbols, the symbols must be resolved into actual addresses.

    | Symbol     | Memory location |

    | :-------   | :----------:    |

    | i          | 16              |

    | sum        | 17              |

    | LOOP       | 4               |

    | END        | 18              |

    The table above is the symbol table for the program above. Since in Hack system we allocate memory for variable from memory 16 so the memory location for variable *i* will be 16 and *sum* will be 17. To specify label *LOOP* and *END* we count the number of instructions in the program so that *LOOP* will be4 and *END* will be 18.