ST STM32F405 Reference Manual page 1063

RM0090
Bit 11 SDIOSuspend: SD I/O suspend command
Bit 10 CPSMEN: Command path state machine (CPSM) Enable bit
Bit 9 WAITPEND: CPSM Waits for ends of data transfer (CmdPend internal signal).
If this bit is set, the CPSM waits for the end of data transfer before it starts sending a
command.
Bit 8 WAITINT: CPSM waits for interrupt request
Bits 7:6 WAITRESP: Wait for response bits
Bits 5:0 CMDINDEX: Command index
The command index is sent to the card as part of a command message.
Note: After a data write, data cannot be written to this register for three SDIOCLK clock periods
plus two PCLK2 clock periods.
MultiMediaCards can send two kinds of response: short responses, 48 bits long, or long
responses,136 bits long. SD card and SD I/O card can send only short responses, the
argument can vary according to the type of response: the software will distinguish the type
of response according to the sent command. CE-ATA devices send only short responses.
31.9.5 SDIO command response register (SDIO_RESPCMD)
Address offset: 0x10
Reset value: 0x0000 0000
The SDIO_RESPCMD register contains the command index field of the last command
response received. If the command response transmission does not contain the command
index field (long or OCR response), the RESPCMD field is unknown, although it must
contain 111111b (the value of the reserved field from the response).
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
Bits 31:6 Reserved, must be kept at reset value
Bits 5:0 RESPCMD: Response command index
If this bit is set, the command to be sent is a suspend command (to be used only with SDIO
card).
If this bit is set, the CPSM is enabled.
If this bit is set, the CPSM disables command timeout and waits for an interrupt request.
They are used to configure whether the CPSM is to wait for a response, and if yes, which
kind of response.
00: No response, expect CMDSENT flag
01: Short response, expect CMDREND or CCRCFAIL flag
10: No response, expect CMDSENT flag
11: Long response, expect CMDREND or CCRCFAIL flag
Reserved
Read-only bit field. Contains the command index of the last command response received.
Secure digital input/output interface (SDIO)
RM0090 Rev 18
9 8 7 6 5 4 3
RESPCMD
r r r
2 1 0
r r r
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