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©Copyright 2000-2007 SD Card Association
SDIO Simplified Specification Version 2.00
23
Bits
Identifier
Type
Value
Description
Clear
Condition
5-4
IO_CURRENT_STATE S
00=DIS
01=CMD
02=TRN
03=RFU
DIS=Disabled:
Initialize, Standby and Inactive
States (card not selected)
CMD=DAT lines free:
1. Command waiting (No
transaction suspended)
2. Command waiting (All
CMD53 transactions
suspended)
3. Executing CMD52 in CMD
State
TRN=Transfer:
Command executing with data
transfer using DAT[0] or DAT[3:0]
lines
B
3
ERROR E
R
E R X
’0’= no error
’1’= error
A general or an unknown error
occurred during the operation.
Type “E R” shall be used for
CMD52
Type “E R X” shall be used for
CMD53
C
2
RFU --
Fixed at 0
Reserved for Future Use
C
1
FUNCTION_NUMBER
E R
’0’= no error
’1’= error
An invalid function number was
requested
C
0
OUT_OF_RANGE E
R
’0’= no error
’1’= error
The command’s argument was out
of the allowed range for this card.
C
Table 5-1 Flag data for IO_RW_DIRECT SD Response
5.2.2
R5, IO_RW_DIRECT Response (SPI mode)
The SDIO card’s response to CMD52 in the SPI mode is shown in Figure 5-3. If the operation was a read
command, the data being read is returned as an 8-bit value. In addition, 8 bits of status information is returned in
a SPI R1 response byte as described in Fig 47 of the SD Physical Specification modified for I/O as shown in
Figure 5-3.
Figure 5-3 IO_RW_DIRECT Response in SPI Mode
Note the read/write (R/W) data is identical to the read/write data described for the SD R5 response (see 5.2.1).
Parameter error status in SPI mode corresponds to OUT_OF_RANGE and ERROR in the SD mode response.
In the case of CMD53, Data Error Token should also be used to indicate OUT_OF_RANGE and ERROR.
1 = in idle state
RFU (always 0)
1 = illegal command
1 = COM CRC error
1 = Function number error
RFU (always 0)
1 = parameter error
Start Bit (always 0)
R/W Data (8 Bits)
0
0
0