Altera Cyclone V Device Handbook page 671

cv_54010
2013.12.30
Lock Operations
The NAND flash controller supports the following features:
• Flash locking The NAND flash controller supports all flash locking operations.
The flash device itself might have limited support for these functions. If the device does not support
locking functions, the flash controller ignores these commands.
• Lock-tight With the lock-tight feature, the NAND flash controller can prevent lock status from being
changed. After the memory is locked tight, the flash controller must be reset before any flash area can be
locked or unlocked.
Unlocking a Span of Memory Blocks
To unlock several blocks of memory, perform the following steps:
1. Write to the command register, setting the CMD_MAP field to 2 and the BLK_ADDR field to the starting
address of the area to unlock.
2. Write 0x10 to the Data register.
3. Write to the command register, setting the CMD_MAP field to 2 and the BLK_ADDR field to the ending
address of the area to unlock.
4. Write 0x11 to the Data register.
When unlocking a range of blocks, the start block address must be less than the end block address. Otherwise,
the NAND flash controller exhibits undetermined behavior.
Locking All Memory Blocks
To lock the entire memory:
1. Write to the command register, setting the CMD_MAP field to 2 and the BLK_ADDR field to any memory
address.
2. Write 0x21 to the Data register.
Setting Lock-Tight on All Memory Blocks
After the lock-tight is applied, unlocked areas cannot be locked, and locked areas cannot be unlocked. To
lock-tight the entire memory:
1. Write to the command register, setting the CMD_MAP field to 2 and the BLK_ADDR field to any memory
address.
2. Write 0x31 to the Data register.
To disable the lock-tight, reset the memory controller.
Transfer Mode Operations
You can configure the NAND flash controller in one of the following modes of data transfer:
• Default area transfer mode
• Spare area transfer mode
• Main+spare area transfer mode
The NAND flash controller determines the default transfer mode from the setting of
transfer_spare_reg register in the config group. Use MAP10 commands to dynamically change
the transfer mode from the existing mode to the new mode. All subsequent commands are in the new mode
NAND Flash Controller
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Lock Operations
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