Hands-On Embedded Programming with C++17

8-bit means 8 bits

Not surprisingly, the use of 16-bit and 32-bit integers on 8-bit MCUs is pretty slow. This is because the system has to perform multiple operations on the same integer value, as it can only fit 8 bits into its registers at a time.

Similarly, the use of floating-point variables on a system without a floating-point unit (FPU) means that such operations are highly suitable for slowing a system down to a crawl as the integer-only processor struggles to keep up with a flow of instructions aimed at simulating floating-point operations.