Altera Cyclone V Device Handbook page 743

cv_54011
2013.12.30
• start_cmd = 1
• disable_boot = 1
• card_number = 0
• All other fields = 0
The controller generates a Command Done interrupt after deasserting the CMD line of the card. In
internal DMA controller mode, the descriptor is closed and the ces bit in the idsts register is set
to 1, indicating a Boot Data Start timeout.
b. If a Boot Data Start interrupt is received, it indicates that the boot data is being received from the card
device. When the DMA engine is not in internal DMA controller mode, the software driver can then
initiate a data read from the controller based on the rxdr interrupt bit in the rintsts register.
In internal DMA controller mode, the DMA engine starts transferring the data from the FIFO buffer
to the system memory as soon as the level specified in the rx_wmark field of the fifoth register
is reached.
At the end of a successful boot data transfer from the card, the following interrupts are generated:
• The cmd bit and dto bit in the rintsts register
• The ri bit in the idsts register, in internal DMA controller mode only
c. In internal DMA controller mode:
• If the software driver creates more descriptors than required by the received boot data, the extra
descriptors are not closed by the controller.
• If the software driver creates fewer descriptors than required by the received boot data, the controller
generates a Descriptor Unavailable interrupt and does not transfer any further data to system
memory.
The boot operation for eMMC card devices is complete.
Related Information
• Clock Setup
Refer to this section for information on how to set the card device frequency.
• Internal DMA Controller Transmission Sequences
Refer to this section for information about the Internal DMA Controller Transmission Sequences.
• Internal DMA Controller Reception Sequences
Refer to this section for information about the Internal DMA Controller Reception Sequences.
Boot Operation for Removable MMC4.3, MMC4.4 and MMC4.41 Cards
Removable MMC4.3, MMC4.4, and MMC4.41 Differences
Removable MMC4.3, MMC4.4, and MMC4.41 cards differ with respect to eMMC in that the controller is
not aware whether these cards support the boot mode of operation when plugged in. Thus, the controller
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must:
1. Discover these cards as it would discover MMC4.0/4.1/4.2 cards for the first time
2. Know the card characteristics
3. Decide whether to perform a boot operation or not
SD/MMC Controller
Send Feedback
Boot Operation for Removable MMC4.3, MMC4.4 and MMC4.41 Cards
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on page 11-34
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on page 11-46
on page 11-47
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11-65
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Altera Corporation