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©Copyright 2000-2007 SD Card Association
SDIO Simplified Specification Version 2.00
9
CMD58
Check Response
Set New Voltage (if needed)
ACMD41 Arg=HCS, WV
Check Response
C
OCR valid
IDLE=1
1sec Timeout
IDLE=0
Test MEM Flag
D
MEM=1
CMD58
Test Flags
Not SD
Card
IO Only
Card
Unusable card
OCR invalid
IO=0, MEM=1
IO=1,
MEM=0
IO=1, MEM=1
High Capacity Support Host: HCS=1
If F8=1, CMD58 is required
to get CCS. If F8=0, CSS=0.
Illegal Command
IO=0, MEM=0
Illegal Command
Memory Initialized
Skip memory initialize or MEM=1
Execute memory initialize & MEM=0
Get memory OCR
Standard
Capacity
Memory
Only Card
High
Capacity
Memory
Only Card
Standard
Capacity
Combo
Card
High
Capacity
Combo
Card
Test CCS
Test CCS
CCS=0
CCS=1
CCS=0
CCS=1
Variables
NF:
Number of I/O Functions (CMD5 Response)
MP: Memory
Present
Flag (CMD5 Response)
IORDY: I/O Power-up Status (C bit in the CMD5 response)
MRDY:
Memory Power-up Status (OCR Bit31)
HCS:
Host Capacity Support (ACMD41 Argument)
CCS:
Card Capacity Status (ACMD41 Response)
Flags
IO:
I/O Functions Initialized Flag
MEM:
Memory Initialized Flag
F8: CMD8
Flag
Figure 3-3 Card initialization flow in SPI mode (SDIO aware host)