Table 162. Au_Size Field; Table 163. Maximum Au Size; Table 164. Erase Size Field - ST STM32F405 Reference Manual

Secure digital input/output interface (SDIO)
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.
00h
01h
02h
03h
04h
05h
06h
07h
08h
09h
Ah – Fh
The maximum AU size, which depends on the card capacity, is defined in
card can be set to any AU size between RU size and maximum AU size.
Capacity
Maximum AU Size
ERASE_SIZE
This 16-bit field indicates NERASE. When NERASE numbers of AUs are erased, the
timeout value is specified by ERASE_TIMEOUT (Refer to ERASE_TIMEOUT). The host
should determine the proper number of AUs to be erased in one operation so that the host
can show the progress of the erase operation. If this field is set to 0, the erase timeout
calculation is not supported.
ERASE_SIZE
0000h
0001h
0002h
0003h
---------
FFFFh
1048/1749

Table 162. AU_SIZE field

AU_SIZE

Table 163. Maximum AU size

16 MB-64 MB
512 KB

Table 164. Erase size field

Erase timeout calculation is not supported.
1 AU
2 AU
3 AU
---------
65535 AU
RM0090 Rev 18
Value definition
Not defined
16 KB
32 KB
64 KB
128 KB
256 KB
512 KB
1 MB
2 MB
4 MB
Reserved
128 MB-256 MB
1 MB 2 MB
Value definition
RM0090
Table 163. The
512 MB 1 GB-32 GB
4 MB