SanDisk SDSDH-1024 Product Manual - Page 62

Relation between ACMD6 and Lock/Unlock State

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Revision 2.2 Chapter 4 - SD Card Protocol Description SanDisk SD Card Product Manual 4.4.8 Table 4-7 Force Erase Function to Locked Card CMD42 Parameter PWP14 Bit3 Bit2 Bit1 Bit0 1 0 0 0 Yes TWP15 GWP16 Don't care Result of the Function Error17 Card Status Bit25 Bit24 1 1 1 0 0 0 No Yes Execute force erase & clear 1 to 0 0 Temporary Write Protect and Group Write Protect18 1 0 0 0 No No Execute force erase 1 to 0 0 • Relation between ACMD6 and Lock/Unlock State ACMD6 is rejected when the card is locked and bus width can be changed only when the card is unlocked. Figure 4-11 shows the relation between ACMD6 and Lock / Unlock state. Table 4-8 Relationship between ACMD6 and Lock/Unlock State Card State Bus Mode Result of the Function Unlocked 1-bit ACMD6 is accepted Locked 1-bit ACMD6 is rejected and remains in 1-bit mode Unlocked 4-bit ACMD6 is accepted Locked 4-bit ACMD6 is rejected and remains in 4-bit mode; CMD0 changes to 1-bit mode Note: After power on (in 1-bit mode), if the card is locked, the SD mode host shall issue CMD42 in 1-bit mode. If the card is locked in 4-bit mode, the SD mode host shall issue CMD42 in 4-bit mode. • Commands Accepted for Locked Card The locked card will accept commands listed below and return a response with setting CARD_IS_LOCKED. − Basic class (0) − Lock card class (7) − CMD16 − ACMD41 All other commands (including security commands) are treated as illegal commands. Note: After power on, the host can recognize the card lock/unlock state by the CARD_IS_LOCKED in the response of CMD7 or CMD13. Application-specific Commands The SanDisk SD Card is defined to be protocol-forward-compatible to the MultiMediaCard Standard. The SD Card system is designed to provide a standard interface for a variety application types. In order to keep future compatibility to the MultiMediaCard standard together with 14 Write Protection PWP: Permanent Write Protect (CSD bit13). 15 Write Protection TWP: Temporary Write Protect (CSD bit12). 16 Write Protection GWP: Group Write Protect (CMD28, CMD29, CMD30). 17 Refer to Note 2 in Table 4-6. 18 Refer to Note 3 in Table 4-6. © 2004 SanDisk Corporation 4-18 12/08/04

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Chapter 4 – SD Card Protocol Description
Revision 2.2
SanDisk SD Card Product Manual
© 2004 SanDisk Corporation
4-18
12/08/04
Table 4-7
Force Erase Function to Locked Card
CMD42 Parameter
TWP
15
Card Status
Bit3
Bit2
Bit1
Bit0
PWP
14
GWP
16
Result of the Function
Bit25
Bit24
1
0
0
0
Yes
Don’t care
Error
17
1
1
1
0
0
0
No
Yes
Execute force erase & clear
Temporary Write Protect and
Group Write Protect
18
1 to 0
0
1
0
0
0
No
No
Execute force erase
1 to 0
0
•
Relation between ACMD6 and Lock/Unlock State
ACMD6 is rejected when the card is locked and bus width can be changed only when the
card is unlocked. Figure 4-11 shows the relation between ACMD6 and Lock / Unlock state.
Table 4-8
Relationship between ACMD6 and Lock/Unlock State
Card State
Bus Mode
Result of the Function
Unlocked
1-bit
ACMD6 is accepted
Locked
1-bit
ACMD6 is rejected and remains in 1-bit mode
Unlocked
4-bit
ACMD6 is accepted
Locked
4-bit
ACMD6 is rejected and remains in 4-bit mode; CMD0 changes to 1-bit
mode
Note:
After power on (in 1-bit mode), if the card is locked, the SD mode host shall issue
CMD42 in 1-bit mode. If the card is locked in 4-bit mode, the SD mode host shall issue
CMD42 in 4-bit mode.
•
Commands Accepted for Locked Card
The locked card will accept commands listed below and return a response with setting
CARD_IS_LOCKED.
−
Basic class (0)
−
Lock card class (7)
−
CMD16
−
ACMD41
All other commands (including security commands) are treated as illegal commands.
Note:
After power on, the host can recognize the card lock/unlock state by the
CARD_IS_LOCKED in the response of CMD7 or CMD13.
4.4.8
Application-specific Commands
The SanDisk SD Card is defined to be protocol-forward-compatible to the MultiMediaCard
Standard.
The SD Card system is designed to provide a standard interface for a variety application
types. In order to keep future compatibility to the MultiMediaCard standard together with
14
Write Protection
PWP
:
Permanent Write Protect (CSD bit13).
15
Write Protection
TWP
:
Temporary Write Protect (CSD bit12).
16
Write Protection
GWP
:
Group Write Protect (CMD28, CMD29, CMD30).
17
Refer to Note 2 in Table 4-6.
18
Refer to Note 3 in Table 4-6.