ST STM32F40 Series

RM0090 Secure digital input/output interface (SDIO)
Doc ID 018909 Rev 4 874/1422
PERFORMANCE_MOVE
This 8-bit field indicates Pm (performance move) and the value can be set by 1 [MB/sec]
steps. If the card does not move used RUs (recording units), Pm should be considered as
infinity. Setting the field to FFh means infinity.
AU_SIZE
This 4-bit field indicates the AU size and the value can be selected in the power of 2 base
from 16 KB.
Table 138. Speed class code field
SPEED_CLASS Value definition
00h Class 0
01h Class 2
02h Class 4
03h Class 6
04h – FFh Reserved
Table 139. Performance move field
PERFORMANCE_MOVE Value definition
00h Not defined
01h 1 [MB/sec]
02h 02h 2 [MB/sec]
--------- ---------
FEh 254 [MB/sec]
FFh Infinity
Table 140. AU_SIZE field
AU_SIZE Value definition
00h Not defined
01h 16 KB
02h 32 KB
03h 64 KB
04h 128 KB
05h 256 KB
06h 512 KB
07h 1 MB
08h 2 MB