K60P100M100SF2RM Datasheet, PDF (1653/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Chapter 52 Secured digital host controller (SDHC)
5. Set the SDHC block length register to be the same as the block length set for the card
in Step 2.
6. Set the SDHC number block register (NOB), nob is 5 (for instance).
7. Disable the buffer read ready interrupt, configure the DMA setting and enable the
eSDHC DMA when sending the command with data transfer. The AC12EN bit
should also be set
8. Set the SABGREQ bit.
9. Wait for the Transfer Complete interrupt.
10. Clear the SABGREQ bit.
11. Check the status bit to see if read CRC error occurred.
12. Set the CREQ bit to continue the read operation.
13. Wait for the Transfer Complete interrupt.
14. Check the status bit to see if a read CRC error occurred, or some another error,
occurred during the auto12 command sending and response receiving.
Like the write operation, it is possible to meet the ending block of the transfer when
paused. In this case, the SDHC will ignore the Stop At Block Gap Request and treat it as
a command read operation.
Unlike the write operation, there is no remaining data inside the buffer when the transfer
is paused. All data received before the pause will be transferred to the Host System. No
matter if the Suspend Command is sent or not, the internal data buffer is not flushed.
If the Suspend Command is sent and the transfer is later resumed by means of a Resume
Command, the SDHC takes the command as a normal one accompanied with data
transfer. It is left for the Driver to set all the relevant registers before the transfer is
resumed. If there is only one block to send when the transfer is resumed, the MSBSEL
and BCEN bits of the Transfer Type register are set, as well as the AC12EN bit.
However, the SDHC will automatically send the CMD12 to mark the end of multi-block
transfer.
52.6.3.3 Suspend resume
The SDHC supports the suspend resume operations of SDIO cards, although slightly
different than the suggested implementation of Suspend in the SDIO card specification..
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.
1653