NOTES
Setup and Use of the Multimedia Card/Secure Digital Host Controller Application Note, Rev. 0
Freescale Semiconductor
13
Страница 1: ...odule The document also describes the interface of the MMC SD modules specifically the card identification mode and the system clock controller along with example code System considerations at various...
Страница 2: ...interrupt detection during 1 or 4 bit access 2 1 Multimedia Card MMC Protocol The MMC is low cost data storage and communication medium implemented as a hardware card with a simple control unit and a...
Страница 3: ...SD I O Card depending on implementation Both RCA Relative Card Address Assigned by the MMC SD module during initialization 16 Both DSR Driver Stage Configures the card s output drivers Use is optiona...
Страница 4: ...DDIR is not necessarily required to initialize however it is highly recommended especially when working with multiple modules Example 1 Pin Configuration for MMC SD Card on the i MX1 L Initialize Set...
Страница 5: ...e next three registers PSR0_2 PSR1_2 and PAR_2 are used to allow the IP bus peripheral to send 32 bits and whether it can be accessed in user mode 4 Interfacing with the MMC SD Module This section des...
Страница 6: ...ime out has occurred then check for the MMC card by sending the SEND_OP_COND CMD1 command and check again for a time out If a time out occurs after CMD1 then the following possibilities may have occur...
Страница 7: ...ode sample to configure the clock with an output frequency of 406 25 kHz For the i MX21 there is an extra gate used for each peripheral clock to conserve power when other peripherals are not in use Th...
Страница 8: ...128 MHz 101 563 kHz CLK_RATE 0x5 4 3 Data Transfer Mode After the card identification mode is set it is then switched over to the transfer state where it waits for either a write or read command This...
Страница 9: ...the MMC SD card occurs during the data transfer mode Commands for reading data are as follows CMD17 READ_SINGLE_BLOCK CMD18 READ_MULTIPLE_BLOCK CMD30 SEND_WRITE_PROT CMD56 GEN_CMD ACMD51 SEND_SCR Afte...
Страница 10: ...d The Stream Mode is not supported in any of the three processors 5 Special Considerations The MMC SD module varies in speed during the data transfer mode Table 3 and Table 4 describe the various spee...
Страница 11: ...ait for data transfer to complete 6 References The following reference documents are used in conjunction with this document for configuration of the MMC SD module 6 1 Freescale Semiconductor Documents...
Страница 12: ...rcad File 6 AN2906 MMC SD Host Controller Addendum Application Note order number AN2906 6 2 Standard Documents The following standard documentations were used as reference for this application note an...
Страница 13: ...NOTES Setup and Use of the Multimedia Card Secure Digital Host Controller Application Note Rev 0 Freescale Semiconductor 13...
Страница 14: ...ticular purpose nor does Freescale Semiconductor assume any liability arising out of the application or use of any product or circuit and specifically disclaims any and all liability including without...
