There are bit-addressable CPUs and DSPs. Examples are many microcontrollers (part of the memory accessible in bit-addressable windows), and famous TMS34010 (htt

There are bit-addressable CPUs and DSPs. Examples are many microcontrollers (part of the memory accessible in bit-addressable windows), and famous TMS34010 (https://en.wikipedia.org/wiki/TMS34010 https://en.wikipedia.org/wiki/TMS34010). 4-bit CPUs (like the one in your toothbrush or thermometer) can also of course address 4-bit "words", "bytes" or nibbles. So 8 bits might not be the smallest addressable memory unit.