from reference manual (i.MX25 Multimedia Applications Processor Reference Manual, Rev. 2), I get the following definitions:
RSDT = Software reset for DAT line. Resets part of the data circuit and the DMA circuit.
RSTC = Software reset for CMD line. Resets part of the command circuit.
RSTA = Software reset for all.
Is RSTA reset equivalent to RSDT plus RSTC reset?