Can anyone recommend a decent book(s) which specialises in the s5 100u CPU range of programmers - Most books seem to assume a lot of prior knowledge and often jump way forward without a proper explanation. Thanks for any assistance here!
There are some very good reference books written by Hans Berger, commonly known as "Berger books". There's one for each of the families of S5. If I remember correctly, the book for the 100U series is a primer with plenty of examples.