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05/Memory

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Nemo 2020-05-28 18:07:07 +05:30
parent 262e336fcd
commit 69a32190dc
4 changed files with 110 additions and 36 deletions
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7
NOTES.md
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@ -39,5 +39,8 @@ Fill.asm
}
```
So every "cycle" of the loop, we are coloring an entire row. The row is decided by R0, which is set to @SCREEN at the start. So if you press a key while we are on the middle of the loop (say 120th row), everything from that row onwards would get painted in black, and then the loop resets r0=*screen once we cross the limits. The next iteration of the loop then starts filling the white pixels we'd left in the previous iteration. I kept the smallest paint unit as the row, but it doesn't really matter that much. The only difference is that I'm reading kbd a total of 256 times to paint the screen. Reading once per register also would work, and reading once per "screenfill" would also work. But that changes the 'delay' b/w your keyboard press and the screen fill start. I thought per row was a good compromise.
**assembly**: Since our assembly doesn't have any functions, writing Assembly is much tougher than I thought it would be. All state is global, there are no functions, and you can only jump using goto.
So every "cycle" of the loop, we are coloring an entire row. The row is decided by R0, which is set to @SCREEN at the start. So if you press a key while we are on the middle of the loop (say 120th row), everything from that row onwards would get painted in black, and then the loop resets r0=\*screen once we cross the limits. The next iteration of the loop then starts filling the white pixels we'd left in the previous iteration. I kept the smallest paint unit as the row, but it doesn't really matter that much. The only difference is that I'm reading kbd a total of 256 times to paint the screen. Reading once per register also would work, and reading once per "screenfill" would also work. But that changes the 'delay' b/w your keyboard press and the screen fill start. I thought per row was a good compromise.
Memory
: Started by using a Mux4Way16, but then decided against making the same mistake I did in PC. Switched to 2 Mux16s instead.

2
README.md
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@ -61,7 +61,7 @@ Counting number of instructions by `wc -l $file.hack`
## [Project 5: Computer Architecture](https://www.nand2tetris.org/project05)
- [ ] `Memory.hdl`
- [x] `Memory.hdl` (2xMux16, 2xNot, 3xAnd)
- [ ] `CPU.hdl`
- [ ] `Computer.hdl`

19
projects/05/Memory.hdl
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@ -27,5 +27,22 @@ CHIP Memory {
OUT out[16];
PARTS:
// Put your code here:
// loadscreen = address[14] && (!address[13]) && load
Not(in=address[13], out=notkbd);
And(a=address[14], b=notkbd, out=pickscreen);
And(a=pickscreen,b=load, out=loadscreen);
// loadram = !address[14] && load
Not(in=address[14], out=pickram);
And(a=pickram,b=load, out=loadram);
RAM16K(in=in,load=loadram,address=address[0..13], out=ramout);
// This is only called if MSB(address) == 1
Screen(in=in, load=loadscreen, address=address[0..12], out=screenout);
Keyboard(out=kbdout);
// MSB(0|1) = RAM|(screen|keyboard)
Mux16(a=ramout, b=kbdorscreenout, sel=address[14], out=out);
// address[13] = screen|keyboard
Mux16(a=screenout, b=kbdout, sel=address[13], out=kbdorscreenout);
}

54
projects/05/Memory.out Normal file
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@ -0,0 +1,54 @@
| in |load | address | out |
| -1 | 1 | 000000000000000 | 0 |
| -1 | 1 | 000000000000000 | -1 |
| 9999 | 0 | 000000000000000 | -1 |
| 9999 | 0 | 000000000000000 | -1 |
| 9999 | 0 | 010000000000000 | 0 |
| 9999 | 0 | 100000000000000 | 0 |
| 2222 | 1 | 010000000000000 | 0 |
| 2222 | 1 | 010000000000000 | 2222 |
| 9999 | 0 | 010000000000000 | 2222 |
| 9999 | 0 | 010000000000000 | 2222 |
| 9999 | 0 | 000000000000000 | -1 |
| 9999 | 0 | 100000000000000 | 0 |
| 9999 | 0 | 000000000000001 | 0 |
| 9999 | 0 | 000000000000010 | 0 |
| 9999 | 0 | 000000000000100 | 0 |
| 9999 | 0 | 000000000001000 | 0 |
| 9999 | 0 | 000000000010000 | 0 |
| 9999 | 0 | 000000000100000 | 0 |
| 9999 | 0 | 000000001000000 | 0 |
| 9999 | 0 | 000000010000000 | 0 |
| 9999 | 0 | 000000100000000 | 0 |
| 9999 | 0 | 000001000000000 | 0 |
| 9999 | 0 | 000010000000000 | 0 |
| 9999 | 0 | 000100000000000 | 0 |
| 9999 | 0 | 001000000000000 | 0 |
| 9999 | 0 | 010000000000000 | 2222 |
| 1234 | 1 | 001001000110100 | 0 |
| 1234 | 1 | 001001000110100 | 1234 |
| 1234 | 0 | 010001000110100 | 0 |
| 1234 | 0 | 110001000110100 | 0 |
| 2345 | 1 | 010001101000101 | 0 |
| 2345 | 1 | 010001101000101 | 2345 |
| 2345 | 0 | 000001101000101 | 0 |
| 2345 | 0 | 100001101000101 | 0 |
| 2345 | 0 | 110000000000000 | 75 |
| -1 | 1 | 100111111001111 | -1 |
| -1 | 1 | 101000001001111 | -1 |
| -1 | 1 | 000111111001111 | 0 |
| -1 | 1 | 010111111001111 | 0 |
| -1 | 0 | 100111111001110 | 0 |
| -1 | 0 | 100111111001101 | 0 |
| -1 | 0 | 100111111001011 | 0 |
| -1 | 0 | 100111111000111 | 0 |
| -1 | 0 | 100111111011111 | 0 |
| -1 | 0 | 100111111101111 | 0 |
| -1 | 0 | 100111110001111 | 0 |
| -1 | 0 | 100111101001111 | 0 |
| -1 | 0 | 100111011001111 | 0 |
| -1 | 0 | 100110111001111 | 0 |
| -1 | 0 | 100101111001111 | 0 |
| -1 | 0 | 100011111001111 | 0 |
| -1 | 0 | 101111111001111 | 0 |
| -1 | 0 | 110000000000000 | 89 |