The initial implementation is based on the Specs v1.10 (see a1bb27b1e9).
However the SCR is anouncing the card being v1.01.
The new chapters added in version 1.10 are:
4.3.10 Switch function command
Switch function command (CMD6) 1 is used to switch or expand
memory card functions. [...]
This is a new feature, introduced in SD physical Layer
Specification Version 1.10. Therefore, cards that are
compatible with earlier versions of the spec do not support
it. The host shall check the "SD_SPEC" field in the SCR
register to recognize what version of the spec the card
complies with before using CMD6. It is mandatory for SD
memory card of Ver1.10 to support CMD6.
4.3.11 High-Speed mode (25MB/sec interface speed)
Though the Rev 1.01 SD memory card supports up to 12.5MB/sec
interface speed, the speed of 25MB/sec is necessary to support
increasing performance needs of the host and because of memory
size which continues to grow.
To achieve 25MB/sec interface speed, clock rate is increased to
50MHz and CLK/CMD/DAT signal timing and circuit conditions are
reconsidered and changed from Physical Layer Specification
Version 1.01.
4.3.12 Command system (This chapter is newly added in version 1.10)
SD commands CMD34-37, CMD50, CMD57 are reserved for SD command
system expansion via the switch command.
[These commands] will be considered as illegal commands (as
defined in revision 1.01 of the SD physical layer specification).
The SWITCH_FUNCTION is implemented since the first commit, a1bb27b1e9.
The 25MB/sec High-Speed mode was already updated in d7ecb86752.
The current implementation does not implements CMD34-37, CMD50 and
CMD57, thus these commands already return ILLEGAL.
With this patch, the SCR register now matches the description of the header:
* SD Memory Card emulation as defined in the "SD Memory Card Physical
* layer specification, Version 1.10."
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20180607180641.874-2-f4bug@amsat.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
9e1245795f