It would be easy to assume that a 32-bit microcontroller would need 32-bits (or four Bytes) for each instruction and that an 8-bit microcontroller would need 8-bits (or one Byte) for each instruction. That would mean a 32-bit microcontroller would need four times as much program memory as an 8-bit microcontroller and two times as much program memory as a 16-bit microcontroller. However, this is not true. In fact, code size on a 32-bit Cortex-M0 processor can actually be less than the code size for an 8-bit processor. Sometimes as much as a quarter or half as much.