Card Status Register - ST STM32F40 Series Reference Manual

Secure digital input/output interface (SDIO)
1. Select a card (SELECT/DESELECT_CARD, CMD7), if none is already selected.
2. Set the block length (SET_BLOCKLEN, CMD16) to 1 byte. Only the 8-bit card
lock/unlock byte (byte 0 in
3. Send LOCK/UNLOCK (CMD42) with the appropriate data byte on the data line including
the 16-bit CRC. The data block indicates the mode (ERASE = 1). All other bits must be
zero.
4. When the ERASE bit is the only bit set in the data field, all card contents are erased,
including the PWD and PWD_LEN fields, and the card is no longer locked. When any
other bits are set, the LOCK_UNLOCK_FAILED error bit is set in the card status
register and the card retains all of its data, and remains locked.
An attempt to use a force erase on an unlocked card fails and the LOCK_UNLOCK_FAILED
error bit is set in the card status register.
28.4.11

Card status register

The response format R1 contains a 32-bit field named card status. This field is intended to
transmit the card status information (which may be stored in a local status register) to the
host. If not specified otherwise, the status entries are always related to the previously issued
command.
Table 136
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
869/1422
Table
defines the different entries of the status. The type and clear condition fields in the
Doc ID 018909 Rev 4
149) is sent.
RM0090