[J-core] J-core address errors and other questions

D. Jeff Dionne Jeff at SE-Instruments.com
Tue Jul 12 11:17:06 EDT 2016

On Jul 12, 2016, at 11:08, Rich Felker <dalias at libc.org> wrote:
>> On Tue, Jul 12, 2016 at 05:48:15AM -0700, Robert Ou wrote:
>> As an unrelated question, I would also like to know what happens when
>> the CPU attempts an unaligned read/write or a jump to an unaligned
>> address. From what I can see, the CPU just seems to assume that this
>> doesn't happen and essentially would end up incorrectly rotating
>> various bits around when an unaligned access is attempted. Is this
>> accurate or did I miss a check for alignment somewhere?
> This matches my experience programming it: I'm not getting unaligned
> exceptions but instead corrupt data. I'm not sure whether this is
> intentional or an oversight/bug.

Is just unimplemented behaviour.  It is simple to cause a trap, but it might impact clock frequency. Another place where such a check is unimplemented is illegal instruction decoding.

Both are relatively simple to add.

> Rich
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