Digital Logic Sim. 8 BIT Computer. Another attempt at a good Control Unit.

I have been working on making a filling functional 8 bit computer in Digital Logic Sim.

I am having a lot of Trouble with the Control Unit. I have made many proto types but each one is missing some control capabilities.

I also figured out a work around for making an inc dec register.

The computer in the video above is programmable with 64 bytes of rom


These are the OPP CODES. comment below with a homemade program and I'll program it in and put it in a video

000 00000 BLANK
000 00001 CLEAR REG A, B, AND Y

ALU TO REG Y

000 00010 A+B STORE TO Y
000 00011 A-B STORE TO Y
000 00100 A+B+1 STORE TO Y
000 00101 A-B-1 STORE TO Y

000 00110 NOT A STORE TO Y
000 00111 A AND B STORE TO Y
000 01000 A OR B STORE TO Y
000 01001 A XOR B STORE TO Y

ALU TO REG A

000 01010 A+B STORE TO REG A
000 01011 A-B STORE TO REG A
000 01100 A+B+1 STORE TO REG A
000 01101 A-B-1 STORE TO REG A

000 01110 NOT A STORE TO REG A
000 01111 A AND B STORE TO REG A
000 10000 A OR B STORE TO REG A
000 10001 A XOR B STORE TO REG A

REG Y OUTPUT

000 10010 REG Y OUT STORE REG A
000 10011 REG Y OUT STORE REG B
000 10100 REG Y OUT STORE SHIFT UP
000 10101 REG Y OUT STORE SHIFT DOWN

REG A OUT

000 10110 REG A OUT STORE REG Y
000 10111 REG A OUT STORE SHIFT UP
000 11000 REG A OUT STORE SHIFT DOWN

REG B OUT

000 11001 REG B OUT STORE TO REG Y
000 11010 REG B OUT STORE SHIFT UP
000 11011 REG B OUT STORE SHIFT DOWN

SHIFT REG OUT
000 11100 SHIFT REG OUT STORE Y
000 11101 SHIFT REG OUT STORE A
000 11110 SHIFT REG OUT STORE B
000 11111 SHIFT REG OUT STORE SHIFT UP
001 00000 SHIFT REG OUT STORE SHIFT DOWN

001 00001 INC DATA IN REG Y
001 00010 DEC DATA IN REG Y
001 00011 CLEAR DATA IN REG Y

001 00100 INC DATA IN REG A
001 00101 DEC DATA IN REG A
001 00110 CLEAR DATA IN REG A

001 00111 INC DATA IN REG B
001 01000 DEC DATA IN REG B
001 01001 CLEAR DATA IN REG B

001 01010 CLEAR FLAGS REGISTER


001 01011 I/O STORE TO Y
001 01100 I/O STORE TO A
001 01101 I/O STORE TO B

LOWER FOR BIT ARE RAM

010 0 XXXX STORE REG Y TO RAM
010 1 XXXX STORE RAM TO REG Y

011 0 XXXX STORE REG A TO RAM
011 1 XXXX STORE RAM TO REG A

100 0 XXXX STORE REG B TO RAM
100 1 XXXX STORE RAM TO REG B


LOWER 5 ARE PROGRAM ADDY

101 XXXXX PROGRAM ADDY JUMP
110 XXXXX JUMP IF C OUT
111 XXXXX JUMP IF ZERO FLAG SET

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