
DocID024597 Rev 5
RM0351
SD/SDIO/MMC card host interface (SDMMC)
1575
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).
439: 432
PERFORMANCE_
MOVE
S R
Performance of move indicated by
1 [MB/s] step.
(See below)
(See below)
A
431:428 AU_SIZE
S R
Size of AU
(See below)
(See below)
A
427:424 Reserved
423:408 ERASE_SIZE
S R
Number of AUs to be erased at a
time
(See below)
A
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 274. SD status (continued)
Bits
Identifier
Type
Value
Description
Clear
condition
Table 275. Speed class code field
SPEED_CLASS
Value definition
00h
Class 0
01h
Class 2
02h
Class 4
03h
Class 6
04h – FFh
Reserved