Texas Instruments TMS320DM644x manual MMC/SD Mode Multiple-Block Write Operation Using CPU

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Procedures for Common Operations

3.6MMC/SD Mode Multiple-Block Write Operation Using CPU

To perform a multiple-block write, the same block length needs to be set in both the MMC/SD controller and the card.

Note: The procedure in this section uses a STOP_TRANSMISSION command to end the block transfer. This assumes that the value in the MMC number of blocks counter register (MMCNBLK) is 0. A multiple-block operation terminates itself if you load MMCNBLK with the exact number of blocks you want transferred.

The procedure for this operation is:

1.Write the card’s relative address to the MMC argument registers (MMCARGH and MMCARGL). Load the high part of the address to MMCARGH and the low part of the address to MMCARGL.

2.Read card CSD to determine the card'smaximum block length.

3.Use the MMC command register (MMCCMD) to send the SET_BLOCKLEN command (if the block length is different than the length used in the previous operation). The block length must be a multiple of 512 bytes and less then the maximum block length specified in the CSD.

4.Reset the FIFO (FIFORST bit in MMCFIFOCTL).

5.Set the FIFO direction to transmit (FIFODIR bit in MMCFIFOCTL).

6.Set the access width (ACCWD bits in MMCFIFOCTL).

7.Set the FIFO threshold (FIFOLEV bit in MMCFIFOCTL).

8.Enable the MMC interrupt.

9.Enable DXRDYINT interrupt.

10.Write the first 32 bytes of the data block to the MMC data transmit register (MMCDXR).

11.Use MMCCMD to send the WRITE_MULTI_BLOCK command to the card.

12.Wait for MMC interrupt.

13.Use the MMC status register 0 (MMCST0) to check for errors and to determine the status of the FIFO. If more bytes are to be written and the FIFO is not full, go to step 14. If the all of the data has been written, go to step 15.

14.Write the next n bytes (depends on setting of FIFOLEV in MMCFIFOCTL: 0 = 16 bytes, 1 = 32 bytes) of the data block to MMCDXR, and go to step 12.

15.Use MMCCMD to send the STOP_TRANSMISSION command.

The sequence of events in this operation is shown in Figure 16.

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Multimedia Card (MMC)/Secure Digital (SD) Card Controller

SPRUE30B –September 2006

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Contents Users Guide Submit Documentation Feedback Contents Appendix a List of Figures List of Tables Read This First Trademarks Features Functional Block DiagramPurpose of the Peripheral Supported Use Case Statement Industry Standards Compliance StatementMMC/SD Controller Interface Diagram MMC/SD Controller Clocking Diagram Clock ControlSignal Descriptions MMC/SD Controller Pins Used in Each Mode1 MMC/SD Mode Write Sequence Protocol DescriptionsMMC/SD Mode Write Sequence 2 MMC/SD Mode Read SequencePortion Sequence Description MMC/SD Mode Read Sequence Data Flow in the Input/Output FifoCRC RD CMDFifo Operation Diagram Data Flow in the Data Registers Mmcdrr and Mmcdxr 1st 2nd 3rd 4th Mmcdrr or Mmcdxr registers Support byten =1st 2nd 3rd 4th Support byten = 1111 1110 Fifo Operation During Card Read Operation Edma ReadsCPU Reads Fifo Operation During Card Read Diagram Fifo Operation During Card Write Operation Edma WritesCPU Writes Fifo Operation During Card Write Diagram Reset Considerations InitializationInitializing the Clock Controller Registers Mmcclk Initialize the Interrupt Mask Register MmcimInitialize the Time-Out Registers Mmctor and Mmctod Initialize the Data Block Registers Mmcblen and MmcnblkMonitoring Activity in the MMC/SD Mode Determining Whether New Data is Available in MmcdrrChecking For a Data Transmit Empty Condition Interrupt Support Interrupt Events and RequestsInterrupt Multiplexing Description of MMC/SD Interrupt RequestsPower Management DMA Event SupportEmulation Considerations MMC Card Identification Procedure Card Identification OperationProcedures for Common Operations SD Card Identification Procedure MMC/SD Mode Single-Block Write Operation Using CPU MMC/SD Mode Single-Block Write Operation MMC/SD Mode Single-Block Write Operation Using the Edma MMC/SD Mode Single-Block Read Operation Using the CPUMMC/SD Mode Single-Block Read Operation Using Edma MMC/SD Mode Single-Block Read OperationMMC/SD Mode Multiple-Block Write Operation Using CPU MMC/SD Multiple-Block Write Operation MMC/SD Mode Multiple-Block Write Operation Using Edma MMC/SD Mode Multiple-Block Read Operation Using CPUMMC/SD Mode Multiple-Block Read Operation Using Edma MMC/SD Mode Multiple-Block Read OperationOffset Acronym Register Description MMC Control Register Mmcctl MMC Control Register Mmcctl Field DescriptionsBit Field Value Description MMC Memory Clock Control Register Mmcclk MMC Memory Clock Control Register Mmcclk Field DescriptionsClken Clkrt ClkenMMC Status Register 0 MMCST0 MMC Status Register 0 MMCST0 Field DescriptionsBit Field Write-data CRC error MMC Status Register 1 MMCST1 MMC Status Register 1 MMCST1 Field DescriptionsFifoful Fifoemp DAT3ST Drful Dxemp Clkstp Busy FifofulMMC Interrupt Mask Register Mmcim MMC Interrupt Mask Register Mmcim Field DescriptionsEtrndne Edated Edrrdy Edxrdy EtrndneMMC Response Time-Out Register Mmctor MMC Response Time-Out Register Mmctor Field DescriptionsTOR MMC Data Read Time-Out Register Mmctod MMC Data Read Time-Out Register Mmctod Field DescriptionsMMC Block Length Register Mmcblen MMC Block Length Register Mmcblen Field DescriptionsBlen MMC Number of Blocks Register Mmcnblk MMC Number of Blocks Counter Register MmcnblcMMC Number of Blocks Register Mmcnblk Field Descriptions NblkMMC Data Receive Register Mmcdrr MMC Data Transmit Register MmcdxrMMC Data Receive Register Mmcdrr Field Descriptions MMC Data Transmit Register Mmcdxr Field DescriptionsMMC Command Register Mmccmd MMC Command Register Mmccmd Field DescriptionsDmatrig Dclr Initck Wdatx Strmtp Dtrw Rspfmt Bsyexp PplenStream enable Bit Position Command Register DescriptionCRC7 MMC Argument Register Mmcarghl MMC Argument Register Mmcarghl Field DescriptionsArgh ArglMMC Response Registers MMCRSP0-MMCRSP7 R1, R3, R4, R5, or R6 Response 48 Bits R2 Response 136 BitsBit Position of Response Register MMCRSP4-0MMC Command Index Register Mmccidx MMC Command Index Register Mmccidx Field DescriptionsMMC Data Response Register Mmcdrsp MMC Data Response Register Mmcdrsp Field DescriptionsMMC Fifo Control Register Mmcfifoctl MMC Fifo Control Register Mmcfifoctl Field DescriptionsAccwd Fifolev Fifodir Fiforst AccwdTable A-1. Document Revision History Reference Additions/Modifications/DeletionsAppendix a Important Notice
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