Big Endian, Little Endian… What it means for bytes is well known - in a multi-byte word (for example, the binary representation of an integer on a 32 bit machine), little-endian systems (Intel) will have the byte with the lsb in the lowest address, big-endian systems (IBM/Motorola, etc) will have it in the highest address.

But what does endian-ness mean on bit level ? To rephrase, say I have a file… I write one byte to it, the character ‘A’. It’s 65, so “01000001″ in binary. In that file, what bit will be “the first bit of the file” ? 1 or 0 ?

It seems that this is not defined anywhere, because bytes are the lowest people go on PCs. But sometimes, an answer for this question is needed, say if the byte was received from a serial bit-stream…

Related posts:

1. when bit endianness matters
2. some pondering on design of MIX in Perl
3. perl bit-crunching

This entry was posted on Sunday, November 30th, 2003 at 6:32 pm and is filed under Programming. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.