> If we refer to address width, then the 8086/8088 are "20-bit" machines, the 80286 "24-bit", and P6 "36-bit".
Also MOS 6502/6510 would have been "16-bit" by that standard.
Some ARMv7 designs would be "40-bit" (like Cortex A7 and A15, probably others too). Or alternatively "128-bit", if considering NEON SIMD width! You could have also said they're 16/32/64/128-bit, because some designs had 16/32/64/128 bits wide memory bus. Yet all ARMv7 designs were considered 32-bit.
And the 68000 a 24-bit CPU, and boy did that cause trouble when Apple et. al. moved to later versions where those top 8 address bits were significant, especially since the 68000 was introduced when DRAM was really dear, e.g. the barely usable first Macintosh had only 128KiB, i.e. a program had essentially less address space to use than a split I&D PDP-11, which gave you 64KiB of each, with 8KiB of data space reserved for the stack. Less, because it's macroarchitecture is 32 bit, "wasting" bit and bytes here and there if your DRAM is that constrained.
Also MOS 6502/6510 would have been "16-bit" by that standard.
Some ARMv7 designs would be "40-bit" (like Cortex A7 and A15, probably others too). Or alternatively "128-bit", if considering NEON SIMD width! You could have also said they're 16/32/64/128-bit, because some designs had 16/32/64/128 bits wide memory bus. Yet all ARMv7 designs were considered 32-bit.