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Secure digital input/output interface (SDIO) RM0090

883/1422 Doc ID 018909 Rev 4

Once an SD I/O card has received a CMD5, the I/O portion of that card is enabled to

respond normally to all further commands. This I/O enable of the function within the I/O card

will remain set until a reset, power cycle or CMD52 with write to I/O reset is received by the

card. Note that an SD memory-only card may respond to a CMD5. The proper response for

a memory-only card would be Present memory = 1 and Number of I/O functions = 0. A

memory-only card built to meet the SD Memory Card specification version 1.0 would detect

the CMD5 as an illegal command and not respond. The I/O aware host will send CMD5. If

the card responds with response R4, the host determines the card’s configuration based on

the data contained within the R4 response.

28.5.7 R5 (interrupt request)

Only for MultiMediaCard. Code length: 48 bits. If the response is generated by the host, the

RCA field in the argument will be 0x0.

[39:8] Argument field

39 16 X Card is ready

[38:36] 3 X Number of I/O functions

35 1 X Present memory

[34:32] 3 X Stuff bits

[31:8] 24 X I/O ORC

[7:1] 7 X Reserved

0 1 1 End bit

Table 155. R4b response (continued)

Bit position Width (bits Value Description

Table 156. R5 response

Bit position Width (bits Value Description

47 1 0 Start bit

46 1 0 Transmission bit

[45:40] 6 ‘101000’ CMD40

[39:8] Argument field

[31:16] 16 X

RCA [31:16] of winning

card or of the host

[15:0] 16 X

Not defined. May be used

for IRQ data

[7:1] 7 X CRC7

0 1 1 End bit

ST STM32F40 Series User Manual

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