Atmel Evaluation Kit AT91SAM9X35-EK AT91SAM9X35-EK Data Sheet
Product codes
AT91SAM9X35-EK
600
SAM9X35 [DATASHEET]
11055E–ATARM–10-Mar-2014
34.11 HSMCI Boot Operation Mode
In boot operation mode, the processor can read boot data from the slave (MMC device) by keeping the CMD line low
after power-on before issuing CMD1. The data can be read from either the boot area or user area, depending on register
setting.
after power-on before issuing CMD1. The data can be read from either the boot area or user area, depending on register
setting.
34.11.1 Boot Procedure, Processor Mode
1.
Configure the HSMCI data bus width programming SDCBUS Field in the HSMCI_SDCR register. The
BOOT_BUS_WIDTH field located in the device Extended CSD register must be set accordingly.
BOOT_BUS_WIDTH field located in the device Extended CSD register must be set accordingly.
2.
Set the byte count to 512 bytes and the block count to the desired number of blocks, writing BLKLEN and BCNT
fields of the HSMCI_BLKR Register.
fields of the HSMCI_BLKR Register.
3.
Issue the Boot Operation Request command by writing to the HSMCI_CMDR register with SPCMD field set to
BOOTREQ, TRDIR set to READ and TRCMD set to “start data transfer”.
BOOTREQ, TRDIR set to READ and TRCMD set to “start data transfer”.
4.
The BOOT_ACK field located in the HSMCI_CMDR register must be set to one, if the BOOT_ACK field of the
MMC device located in the Extended CSD register is set to one.
MMC device located in the Extended CSD register is set to one.
5.
Host processor can copy boot data sequentially as soon as the RXRDY flag is asserted.
6.
When Data transfer is completed, host processor shall terminate the boot stream by writing the HSMCI_CMDR
register with SPCMD field set to BOOTEND.
register with SPCMD field set to BOOTEND.
34.11.2 Boot Procedure DMA Mode
1.
Configure the HSMCI data bus width by programming SDCBUS Field in the HSMCI_SDCR register. The
BOOT_BUS_WIDTH field in the device Extended CSD register must be set accordingly.
BOOT_BUS_WIDTH field in the device Extended CSD register must be set accordingly.
2.
Set the byte count to 512 bytes and the block count to the desired number of blocks by writing BLKLEN and BCNT
fields of the HSMCI_BLKR register.
fields of the HSMCI_BLKR register.
3.
Enable DMA transfer in the HSMCI_DMA register.
4.
Configure DMA controller, program the total amount of data to be transferred and enable the relevant channel.
5.
Issue the Boot Operation Request command by writing to the HSMCI_CMDR register with SPCND set to
BOOTREQ, TRDIR set to READ and TRCMD set to “start data transfer”.
BOOTREQ, TRDIR set to READ and TRCMD set to “start data transfer”.
6.
DMA controller copies the boot partition to the memory.
7.
When DMA transfer is completed, host processor shall terminate the boot stream by writing the HSMCI_CMDR
register with SPCMD field set to BOOTEND.
register with SPCMD field set to BOOTEND.