Comment by monocasa
13 days ago
Like a lot of things, the taxonomy kind of breaks down at the edges and arguments can be made either way.
I will throw out there though that ALU width and buses are generally seen as orthogonal to 'bitness' of a processor, and more an implementation detail. The Z80 had a 4bit ALU, but is considered an 8bit CPU. The PDP-8/s and SERV have single bit ALUs, but are considered 12 and 32 bits respectively. The 8088 is considered a 16bit CPU despite having both an 8bit ALU and bus.
'Bitness' is generally defined more as 'what is the width of whatever is the closest thing to a GPR'.
Seconded. If you were an ASM programmer, you’d have no idea it had a 16 bit ALU. All the ops were 32 bit, regardless of what the underlying silicon looked like.