Hi Philippe, On Fri, Feb 19, 2021 at 2:03 AM Philippe Mathieu-Daudé <f4...@amsat.org> wrote: > > On 2/18/21 6:09 PM, Philippe Mathieu-Daudé wrote: > > On 2/16/21 4:46 AM, Bin Meng wrote: > >> The codes to limit the maximum block size is only necessary when > >> SDHC_BLKSIZE register is writable. > > Per "SD Command Generation": > > The Host Driver should not read the SDMA System Address, Block Size > and Block Count registers during a data transaction unless the > transfer is stopped because the value is changing and not stable. > To prevent destruction of registers using data transfer when issuing > command, the 32-bit Block Count, Block Size, 16-bit Block Count and > Transfer Mode registers shall be write protected by the Host > Controller while Command Inhibit (DAT) is set to 1 in the Present > State register. > > Shouldn't we check for !(s->prnsts & SDHC_DATA_INHIBIT) instead?
Yes, for accurate emulation I think we should. Current implementation uses !(s->prnsts & (SDHC_DOING_READ | SDHC_DOING_WRITE)) which eventually is correct, because: SDHC_DATA_INHIBIT bit is set if either SDHC_DAT_LINE_ACTIVE or SDHC_DOING_READ is set (SD Host Controller Spec v7.00 chapter 2.2.9 Present State Register) SDHC_DAT_LINE_ACTIVE bit is set after the end bit of read or write command, and after end bit of read or write command will generate SDHC_DOING_READ or SDHC_DOING_WRITE (SD Host Controller Spec v7.00 chapter 2.2.9 Present State Register) Regards, Bin
