SanDisk SD Card

Revision 2.2Chapter 4 – SD Card Protocol DescriptionSanDisk SD Card Product Manual• Two types of Lock/Unlock CardThere will be two types of lock / unlock function-supported cards. Type 1 is an olderversion of the SD Card, and Type 2 is the new version defined in this specification (v1.10).Table 4-6 shows the difference between these types of cards. The SD cards that supportLock /Unlock and comply with Version 1.01, can take either Type 1 or Type 2. SD cardsthat support Lock / Unlock and comply with Version 1.10, take Type 2.Table 4-6Type 1 vs. Type 2 Card of Lock/Unlock FunctionNote Type 1 Card (older version) Type 2 Card (new version)1 Treat CMD42 Parameter=0011b as 0001b.Treat CMD42 Parameter=0111b as 0101b.Treat CMD42 Parameter=0110b as 0010b.Results of other combinations are Error.2 Execute force erase and set Permanent Write Protect. Ifforce erase is completed, the CARD_IS_LOCKED ischanged from 1 to 0. A priority is given to force erasefrom Permanent Write Protect.3 Execute force erase but Temporary Write Protect andGroup Write Protect are not cleared. It is in need of thehost clear.All results are each an “error.”Results in an “error”A priority is given to PermanentWrite Protect from force erase.Execute force erase and clearTemporary Write Protect andGroup Write Protect.4 CMD42 Parameter=0010 and CMD42 Parameter=0110The result is no error.Card status Bit24 will be 0.Results in an “error”. Cardstatus Bit24 will be 1.Note: The host can use both types of card without checking difference by taking accountof following points.(1) The host should not set the parameters of CMD42 that return error in Table 4-5. (For*1)(2) The host should not issue force erase command if the Permanent Write Protect is set to1, otherwise the Type 1 card cannot be used any more even if the user remembers the password. (For *2)(3) After the force erase, if the Temporary Write Protect is not cleared, the host should clearit. (For *3)• Force Erase Function to the Locked CardFigure 4-5 clarifies the relation between Force Erase and Write Protection. The Force Erasedoes not erase the secure area. The card shall keep locked state during the erase executionand change to unlocked state after the erase of all user area is completed. Similarly, Thecard shall keep Temporary and Group Write Protection during the erase execution and clearWrite Protection after the erase of all user area is completed. In the case of erase erroroccur, the card can continue force erase if the data of error sectors are destroyed.© 2004 SanDisk Corporation 4-17 12/08/04