Am 11.12.2013 08:43, schrieb Michael Ring:
The strb command seems to be the problem, documentation from STM states:

Each I/O port bit is freely programmable, however the I/O port registers have to be accessed as 32-bit words (half-word or byte accesses are not allowed).

So, is there some way to make the bitset operations word-aligned?
Better say 32-bit aligned to avoid confusion. Words in Pascal are 16-bit although I know that you are talking about the CPUs word size...
Are there any good reasons for not doing so?
What when you really have a byte that you want ot access? Then using 32-bit writes/reads could(*) result in unnecessary cycles.

* I don't know about ARM especially, but I know that for e.g. the m68k a 32-bit store is more expensive than a 16-bit or 8-bit store

That said I don't have a solution for your specific problem except by doing it by hand.

Regards,
Sven
_______________________________________________
fpc-devel maillist  -  fpc-devel@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-devel

Reply via email to