ST STM32F446 Series User Manual

Secure digital input/output interface (SDIO) RM0390
1002/1328 RM0390 Rev 4
29.4.12 SD status register
The SD status contains status bits that are related to the SD memory card proprietary
features and may be used for future application-specific usage. The size of the SD Status is
one data block of 512 bits. The contents of this register are transmitted to the SDIO card
host if ACMD13 is sent (CMD55 followed with CMD13). ACMD13 can be sent to a card in
transfer state only (card is selected).
Table 190 defines the different entries of the SD status register. The type and clear condition
fields in the table are abbreviated as follows:
Type:
• E: error bit
• S: status bit
• R: detected and set for the actual command response
• X: detected and set during command execution. The SDIO card Host must poll the card
by issuing the status command to read these bits
Clear condition:
• A: according to the card current state
• B: always related to the previous command. Reception of a valid command clears it
(with a delay of one command)
• C: clear by read
Table 190. SD status
Bits Identifier Type Value Description
Clear
condition
511: 510 DAT_BUS_WIDTH S R
’00’= 1 (default)
‘01’= reserved
‘10’= 4 bit width
‘11’= reserved
Shows the currently defined
databus width that was
defined by
SET_BUS_WIDTH
command
A
509 SECURED_MODE S R
’0’= Not in the mode
’1’= In Secured Mode
Card is in Secured Mode of
operation (refer to the “SD
Security Specification”).
A
508: 496 Reserved
495: 480 SD_CARD_TYPE S R
’00xxh’= SD Memory Cards as
defined in Physical Spec Ver1.01-
2.00 (’x’= don’t care). The
following cards are currently
defined:
’0000’= Regular SD RD/WR Card.
’0001’= SD ROM Card
In the future, the 8 LSBs will
be used to define different
variations of an SD memory
card (each bit will define
different SD types). The 8
MSBs will be used to define
SD Cards that do not comply
with current SD physical
layer specification.
A
479: 448
SIZE_OF_PROTE
CT ED_AREA
S R
Size of protected area (See
below)
(See below) A
447: 440 SPEED_CLASS S R
Speed Class of the card (See
below)
(See below) A

ST STM32F446 Series Specifications

General

Brand	ST
Model	STM32F446 Series
Category	Microcontrollers
Language	English