Altera Cyclone V Device Handbook page 740

11-62
Boot Operation for eMMC Card Device
Boot Operation for eMMC Card Device
The following figure illustrates the steps to perform the boot process for eMMC card devices. The detailed
steps are described following the flow chart.
Figure 11-14: Flow for eMMC Boot Operation
1. The software driver performs the following checks:
• If the eMMC card device supports boot operation (the BOOT_PARTITION_ENABLE bit is set to 1
in the EXT_CSD register of the eMMC card).
• The BOOT_SIZE_MULT and BOOT_BUS_WIDTH values in the EXT_CSD register, to be used
during the boot process.
2. The software sets the following bits:
• Sets masks for interrupts, by setting the appropriate bits to 0 in the intmask register.
• Sets the global int_enable bit of the ctrl register to 1. Other bits in the ctrl register must be
set to 0.
Note: Altera recommends that you write 0xFFFFFFFF to the rintsts and idsts registers to clear
any pending interrupts before setting the int_enable bit. For internal DMA controller
mode, the software driver needs to unmask all the relevant fields in the idinten register.
3. If the software driver needs to use the internal DMA controller to transfer the boot data received, it must
perform the following steps:
Altera Corporation
expect_boot_ack = 1
Step 11
No Start Start Pattern & No
Pattern Boot Data Received
Step 11.a Step 11.b
Successfully
Received Boot
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Start
Step 1
Step 2 to Step 10
Step 12
Start Pattern &
Boot Data Received
Step 11.c Step 12.a
N Timeout
AC
Data
Step 11.f
Stop
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expect_boot_ack = 0
No Boot Data Boot Data
Received Received
Step 12.b
Successfully
Received Boot
Data
SD/MMC Controller
Send Feedback
cv_54011
2013.12.30
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