Chapter 4 – SD Card Protocol Description
Revision 2.2
SanDisk SD Card Product Manual
© 2004 SanDisk Corporation
4-38
12/08/04
ACMD Index
Type
Argument
Resp.
Abbreviation
Command Description
ACMD42 ac
[31:1]
stuff
bits [0]
set_cd
R1 SET_CLR_CARD_DETECT Connect[1]/Disconnect[0]
the 50KOhm pull-up
resistor on CD/DAT3 (pin
1) of the card.
ACMD43
ACMD49
---
---
---
---
Reserved for SD security
applications.
ACMD51 adtc
[31:0]
stuff
bits
R1
SEND_SCR
Reads the SD
Configuration Register
(SCR).
4.9
Card State Transition
Table 4-18 defines the SD card state-transition (dependent on the received command). The
SD Card application-specific command state-transitions can be found in Class 8.
Table
4-18 Card
State
Transition
Table
Current
Status
idle
ready
ident
stby
tran
data
rcv
prg
dis
ina
State Change
Trigger
Changes to
Class
Independent
“Operation
complete”
---
--- --- --- --- ---
--- tran
stby
---
Class 0
CMD0
idle
idle idle idle idle idle
idle idle idle ---
CMD2
---
ident
--- --- --- ---
--- --- --- ---
CMD3
---
--- stby
stby
--- ---
--- --- --- ---
CMD4
---
--- --- stby
--- ---
--- --- --- ---
CMD7, card is
addressed
---
--- --- tran
--- ---
--- --- prg ---
CMD7, card is
not addressed
---
--- --- stby
stby
stby
--- dis --- ---
CMD9
---
--- --- stby
--- ---
--- --- --- ---
CMD10
---
--- --- stby
--- ---
--- --- --- ---
CMD12
---
--- --- --- --- tran
prg --- --- ---
CMD13
---
--- --- stby
tran
data
rcv prg dis ---
CMD15
--- --- --- ina ina ina
ina ina ina ---
Class 2
CMD16
---
--- --- --- tran
---
--- --- --- ---
CMD17
---
--- --- --- data
---
--- --- --- ---
CMD18
---
--- --- --- data
---
--- --- --- ---
Class 4
CMD16
see class 2