Computer.hdl

// This file is part of www.nand2tetris.org
// and the book "The Elements of Computing Systems"
// by Nisan and Schocken, MIT Press.


/**
 * 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:

    // CPU
    CPU (inM=RAMout, instruction=ROMout, reset=reset, writeM=loadRAM,
         outM=RAMin, addressM=RAMaddress, pc=ROMaddress);

    // RAM
    Memory (in=RAMin, load=loadRAM, address=RAMaddress, out=RAMout);

    // ROM
    ROM32K (address=ROMaddress, out=ROMout);
}