Computer.hdl

// This file is part of www.nand2tetris.org
// and the book "The Elements of Computing Systems"
// by Nisan and Schocken, MIT Press.
// File name: projects/05/Computer.hdl

/**
 * The HACK computer, including CPU, ROM and RAM.
 * When reset is 0, the program stored in the computer's ROM executes.
 * When reset is 1, the execution of the program restarts. 
 * Thus, to start a program's execution, reset must be pushed "up" (1)
 * and "down" (0). From this point onward the user is at the mercy of 
 * the software. In particular, depending on the program's code, the 
 * screen may show some output and the user may be able to interact 
 * with the computer via the keyboard.
 */

CHIP Computer {

    IN reset;

    PARTS:
    ROM32K(address=pc-output, out=program-memory-output);
    CPU(inM=data-memory-output, instruction=program-memory-output, reset=reset, outM=data-memory-input, writeM=write-data-memory, addressM=data-memory-address, pc=pc-output);
    Memory(in=data-memory-input, load=write-data-memory, address=data-memory-address, out=data-memory-output);
}