The first thing to realize is that unless the processor has instructions to access specific bits in the bytes (and there are processors with this ability) then the numbering of the bits within the bytes is purely arbitrary and by convention. The statement about the 'typical bit order' for big-endian and little-endian machines sounds to me like a comment I have seen dealing with the traditional allocation of bits in C bit-fields inside a structure, that typically on a big-endian machine, those bit fields will be allocated starting with the MSB, while typically on a little-endian machine, those bit-fields will be allocated starting with the LSB. This only makes a difference if you are using the bit-fields to match hardware or use a union or other type-punning to see the actual value of the underlying word with the bit-fields within it. For your problem, it turns out that due to the difference is how the big word gets broken down into byte, you might want to do something similar to that also, allocating bit fields from the top of the word, and if you do that, then you will find that multi-bit fields become big-endian, with the MSB at the lower 'bit address', but that doesn't come from how the machine itself orders its values, but how you are using them.