VCB components
In VCB you are abstracted away from transistors, diods, etc. implementations of real components. You use logic gates, delay and similar stuff instead.
Adders
Terms:
- Adder — scheme for summation of bits
- Full adder — adder with carry in/out
Full 1-bit adder. Bit A added to bit B.
To construct 4-bit adder, you just need to stack 4 1-bit adders.
Full 4-bit adder. A0-A1-A2-A3 is added to B0-B1-B2-B3.
You obviously can construct 8-bit adder in same manner.
Simple volatile memory
Terms:
- Volatile memory — memory that exists only when electrical current is present
- Persistent memory — memory that stores data even without electricity
1-bit memory is usually implemented via latches, also called as flip-flops.
Flip-flops are harder to model in VCB, since they require feedback loop of some components (when input depends on output). They also may have clock synchronization issues if modelled badly.
https://www.reddit.com/r/VirtualCiruitBoard/comments/xs698a/my_best_stab_so_far_at_memory/
Decoders
2-4, 3-8, 4-16