mirror of
https://github.com/StepanovPlaton/Nand2Tetris.git
synced 2026-04-03 12:20:47 +04:00
34 lines
1.5 KiB
Plaintext
34 lines
1.5 KiB
Plaintext
// 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/5/Memory.hdl
|
|
/**
|
|
* The complete address space of the Hack computer's memory,
|
|
* including RAM and memory-mapped I/O.
|
|
* The chip facilitates read and write operations, as follows:
|
|
* Read: out(t) = Memory[address(t)](t)
|
|
* Write: if load(t-1) then Memory[address(t-1)](t) = in(t-1)
|
|
* In words: the chip always outputs the value stored at the memory
|
|
* location specified by address. If load=1, the in value is loaded
|
|
* into the memory location specified by address. This value becomes
|
|
* available through the out output from the next time step onward.
|
|
* Address space rules:
|
|
* Only the upper 16K+8K+1 words of the Memory chip are used.
|
|
* Access to address>0x6000 is invalid and reads 0. Access to any address
|
|
* in the range 0x4000-0x5FFF results in accessing the screen memory
|
|
* map. Access to address 0x6000 results in accessing the keyboard
|
|
* memory map. The behavior in these addresses is described in the Screen
|
|
* and Keyboard chip specifications given in the lectures and the book.
|
|
*/
|
|
CHIP Memory {
|
|
IN in[16], load, address[15];
|
|
OUT out[16];
|
|
|
|
PARTS:
|
|
DMux(in=load, sel=address[14], a=lr, b=ls);
|
|
RAM16K(in=in, load=lr, address=address[0..13], out=ro);
|
|
Screen(in=in, load=ls, address=address[0..12], out=so);
|
|
Keyboard(out=ko);
|
|
Mux16(a=so, b=ko, sel=address[13], out=o1);
|
|
Mux16(a=ro, b=o1, sel=address[14], out=out);
|
|
} |