SanDisk SD Card

Revision 2.2Chapter 4 – SD Card Protocol DescriptionSanDisk SD Card Product ManualStop Transmission Received after Last Data Block—Card Busy ProgrammingCMDDATHost CommandN CRCyclesCard ResponseHost CommandS T Content CRC E Z Z P *** P S T Content CRC ES T ContentCard is ProgrammingS L ******************************************************************L E Z Z Z Z Z Z ZZStop Transmission Received after Last Data Block—Card becomes BusyCMDS THost CommandN CRCyclesCard ResponseContent CRC E Z Z P *** P S T Content CRCEHost CommandS T ContentDATCard is ProgrammingZ Z Z Z Z Z Z Z Z Z Z S L ********************* LE Z ZZZZZZZErase, Set and Clear Write Protect TimingThe host must first tag the start (CMD32) and end (CMD33) addresses of the range to beerased. The erase command (CMD38), once issued, will erase all the selected write blocks.Similarly, set and clear write protect commands start a programming operation as well. Thecard will signal “busy” (by pulling the DAT line low) for the duration of the erase orprogramming operation. The bus transaction timings are the same as given for stop trancommand in the “Stop Transmission Received after Last Data Block—Card BusyProgramming” diagram above.Re-selecting a Busy CardWhen a busy card, which is currently in the dis state, is reselected it will reinstate its busysignaling on the data line. The timing diagram for this command/response/busy transactionis the same as given for stop tran command in the “Stop Transmission Received after LastData Block—Card becomes Busy” diagram above.4.13 Timing ValuesTable 4-24 defines all timing values.Table 4-24Timing ValuesValue Min. Max. UnitN CR 2 64 Clock cyclesN ID 5 5 Clock cyclesN AC 2 See Note Clock cyclesN RC 8 --- Clock cyclesN CC 8 --- Clock cyclesN WR 2 --- Clock cyclesNote—The host calculates the maximum read access time as follows:N AC (max)= 100 ((TAAC * f PP ) + (100 * NSAC)) ;f PP is the interface clock rate and TAAC & NSAC are given in the CSD Register.© 2004 SanDisk Corporation 4-46 12/08/04