SD/SDIO/MMC card host interface (SDMMC) RM0351
1422/1693 DocID024597 Rev 3
SIZE_OF_PROTECTED_AREA
Setting this field differs between standard- and high-capacity cards. In the case of a
standard-capacity card, the capacity of protected area is calculated as follows:
Protected area = SIZE_OF_PROTECTED_AREA_* MULT * BLOCK_LEN.
SIZE_OF_PROTECTED_AREA is specified by the unit in MULT*BLOCK_LEN.
In the case of a high-capacity card, the capacity of protected area is specified in this field:
Protected area = SIZE_OF_PROTECTED_AREA
SIZE_OF_PROTECTED_AREA is specified by the unit in bytes.
SPEED_CLASS
This 8-bit field indicates the speed class and the value can be calculated by P
W
/2 (where
P
W
is the write performance).
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.
407:402 ERASE_TIMEOUT S R
Timeout value for erasing areas
specified by
UNIT_OF_ERASE_AU
(See below) A
401:400 ERASE_OFFSET S R
Fixed offset value added to erase
time.
(See below) A
399:312 Reserved
311:0 Reserved for Manufacturer
Table 229. SD status (continued)
Bits Identifier Type Value Description
Clear
condition
Table 230. Speed class code field
SPEED_CLASS Value definition
00h Class 0
01h Class 2
02h Class 4
03h Class 6
04h – FFh Reserved
Table 231. Performance move field
PERFORMANCE_MOVE Value definition
00h Not defined
01h 1 [MB/sec]
To Next Page
Loading...
Need help?
General
