Altera cyclone V Technical Reference page 1023

cv_5v4
2016.10.28
The controller generates a Command Done interrupt after deasserting the
interface.
If internal DMA controller mode is used for the boot process, the controller performs the following
steps after the Boot ACK Received timeout:
• The DMA descriptor is closed
• The
• The
c. If the 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
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 set in the
reached.
At the end of a successful boot data transfer from the card, the following interrupts are generated:
• The
• The
d. If an error occurs in the boot ACK pattern (0b010) or an EBE occurs:
• The controller automatically aborts the boot process by pulling the CMD line high
• The controller generates a Command Done interrupt
• The controller does not generate a Boot ACK Received interrupt
• The application aborts the boot transfer
e. 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. Software cannot reuse the descriptors until they are
closed.
• 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.
f. If N
AC
is an error associated with the start or end bit, the SBE or EBE interrupt is also generated.
The boot operation for eMMC card devices is complete. Do not execute the remaining
12.This step handles the case where no start-acknowledge pattern is expected (
step
to 0 in
a. If the Boot Data Start interrupt is not received from the controller within 1 second of initiating the
command
•
start_cmd
•
disable_boot
•
card_number
• 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
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
SD/MMC Controller
Send Feedback
†
bit in the register is set, indicating Boot Data Start timeout
ces idsts
bit of the register is not set
ri idsts
†
†
bit and bit in the
cmd dto
bit in the register, in internal DMA controller mode only
ri idsts
†
†
is violated between data block transfers, the DRTO interrupt is asserted. In addition, if there
†
9).
9), the software driver must write the
(step
†
= 1
†
= 1
†
= 0
†
Boot Operation for eMMC Card Device
†
†
†
†
register
rintsts
†
†
†
cmd
†
pin of the card
CMD
†
interrupt bit in the
rxdr
field of the
rx_wmark fifoth
†
†
†
expect_boot_ack
register with the following fields:
bit in the
ces idsts
14-77
rintsts
register is
†
†
†
†
(step 12).
was set
†
register is set to
Altera Corporation