controlsignals.txt

0: put external input on address bus
1: general register a write enable
2: manual value to instruction pointer
3: general register a read enable
4: program counter write enable
5: program counter output enable
6: general register b write enable
7: general register b read enable
8: alu store a
9: alu subtract
10: alu store b
11: alu output enable
12: instruction register write enable
13: microinstruction counter (do not use!)
14: instruction register output enable
15: general register c write enable
16: read enable general register c
17: general register d output enable
18: general register d write enable
19: external input on data bus
20: memory read enable
21: memory write enable
22: put higher part of instruction to lower part of address bus
23 put higher part of instruction to lower part of data bus
24: clear the microinstruction counter (for jumps)
25: update flag register
26: stack pointer write enable
27: push (aka subtract one from stack pointer because the stack grows downwards)
28: pop (increase stack pointer by one)
29: stack pointer output enable on data bus
30: manual value to stack pointer
31: stack pointer output enable on address bus
32: memory buffer register write enable
33: memory buffer register read enable
34: put data bus on address bus
35: increment alu thingy
36: put address bus on data bus
37: write enable on the address buffer register thing
38: read enable on the address buffer register thing
39: rbp write enable
40: rbp read enable


opcodes:

00000000 is nop
00000001 is move address to a register
00000010 is jump to address
00000011 is jump if zero
00000100 is subtract a value from a register
00000101 is add value to a register
00000110 is test value with a register
00000111 is jump if less than or equal to
00001000 is write a register to memory
00001001 is jump if less than
00001010 is mov address to reg b
00001011 is subtract value from reg b
00001100 is add value to reg b
00001101 is test value with b register
00001110 is write reg b to memory
00001111 is add reg b to reg a and store in a
00010000 is ret instruction
00010001 is call instruction
00010010 is push rbp
00010011 is mov rsp, rbp
00010100 is pop rbp


the sequence in the flags register is that the first bit is zero the second bit is overflow and the third bit is less than