Altera cyclone V Technical Reference page 1025

cv_5v4
2016.10.28
• JEDEC Standard No. 84-A441
• JEDEC Standard No. 84-A44
• JEDEC Standard No. JESD84-A43
4. If the host processor needs to perform a boot operation at the next power-up cycle, it can manipulate
the EXT_CSD register contents by using a SWITCH_FUNC command.
5. After this step, the software driver must power down the card by writing to the
6. From here on, use the same steps as in Alternative Boot Operation for eMMC Card Devices.
Related Information
Enumerated Card Stack
•
Refer to this section for more information on discovering removable MMC cards.
http://www.jedec.org
•
• Alternative Boot Operation for eMMC Card Devices
Refer to this section for information about alternative boot operation steps.
Alternative Boot Operation
The alternative boot operation differs from the previous boot operation in that software uses the SD/SDIO
GO_IDLE_STATE command to boot the card, rather than holding down the CMD line of the card. The
alternative boot operation can be performed only if bit 0 in the BOOT_INFO register is set to 1.
BOOT_INFO is located at offset 228 in the EXT_CSD registers.
For detailed information about alternative boot operation, refer to the following specifications available on
the JEDEC website:
• JEDEC Standard No. 84-A441
• JEDEC Standard No. 84-A44
• JEDEC Standard No. JESD84-A43
Related Information
www.jedec.org
For more information about alternative boot operation, refer to the following JEDEC Standards available
on the JEDEC website: No. 84-A441, No. 84-A44, and No. JESD84-A43.
Alternative Boot Operation for eMMC Card Devices
The following figure illustrates the sequence of steps required to perform the alternative boot operation for
eMMC card devices. The detailed steps are described following the flow chart.
SD/MMC Controller
Send Feedback
on page 14-43
Alternative Boot Operation
†
pwren
on page 14-79
†
14-79
†
register.
†
Altera Corporation