I'm trying to build an 8 bit divider but i can't fin any useful scheme online. Can you help me by building one or drawing a scheme ?
thank you in advance
This is a 4-bit version of the thing. Each combination of 4-bit numbers (8-bit) gives you a different address in the ROM, last 4 digits give the answer. As you can see, if the first 8 digits are all 1, the answer is a fraction and is undefined.
I have the same problem as you(can't upgrade to 8-bit), but maybe a different mind can use this to create an 8-bit version of the thing.
You can make a divider with multiple subtractions. The method is simple: first you try to subtract dividend by divisor x nth power of 2. In here n is the bit number (4-bit, 8-bit or else) then if you can subtract the first bit of solution is 1 else 0 (1xxx or 0xxx for 4-bit for example). Than if it's 1 you alsa make subtraction else don't do it. At the end decrease n by one by one and do this every time. For example:
4-Bit Divison (15 divided by 3):
I made this chip with that algorithm. First, at left there are NOT gates (with blue outputs) they calculate negative of divider without adding one (that one add with carry input) . And the bottom there are OR and NOT gates (with yellow outputs) they calculate overflow for example 1101 divide by 0011 with 3 shift: 1101-0011000 but that 001 can't be in calculation so if there are any 1's in 001 so it's overflow. It can't be subtract. And if it can be subtract so we subtract for next steps, I do it with MUX. I think it can help you with your project but maybe you can optimize it. Because it works with 1000 ticks per second (In normal mode 250-1000) but maybe in CPU's it can slow down CPU much more.