|Re: [hatari-devel] test needed on a 4MB STF|
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Christian Zietz schrieb:
> During column addressing, the following happens:
> A11 ... A20 -> CAS0 ... CAS9 (with 2 MiB),
> A10 ... A18 -> CAS0 ... CAS8 (with 512 kiB),
> A9 ... A16 -> CAS0 ... CAS7 (with 128 kiB).
> This explains why you can see A9 on both RAS8 and CAS0 with 128 kiB
> configuration. I'd have to recheck what happens to CAS8/CAS9 when 128
> kiB or 512 kiB are set.
OK, found it: In 512 k mode, CAS9 interestingly is A19, in 128 k mode
CAS8 and CAS9 are A17 and A18, respectively. Hence, the mapping becomes:
A11 ... A20 -> CAS0 ... CAS9 (with 2 MiB),
A10 ... A19 -> CAS0 ... CAS9 (with 512 kiB),
A9 ... A18 -> CAS0 ... CAS9 (with 128 kiB).
Again, currently only checked for the IMP MMU.
Christian Zietz - CHZ-Soft - czietz@xxxxxxx
PGP/GnuPG-Key-ID: 0x52CB97F66DA025CA / 0x6DA025CA