Altera cyclone V Technical Reference page 849

13-28
Configure for Default Area Access
transfer_spare_reg
1
1
Related Information
MAP10 Commands
Configure for Default Area Access
You only need to configure for default area access if the transfer mode was previously changed to spare
area or main+spare area. To configure default area access:
1. Write to the command register, setting the
2. Write 0x42 to the
The NAND flash controller determines the default area transfer mode from the setting of the
transfer_spare_reg
+spare area, otherwise it is main area.
Configure for Spare Area Access
To access only the spare area of the flash device, use the MAP10 command to set up the NAND flash
controller to read or write only the spare area on the device. After the flash controller is set up, use MAP01
read and write commands to access the spare area of the appropriate block and page addresses. To
configure the NAND flash controller to access the spare area only, perform the following steps:
1. Write to the command register, setting the
2. Write 0x41 to the
Configure for Main+Spare Area Access
To configure the NAND flash controller to access the main+spare area:
1. Write to the command register, setting the
block.
2. Write 0x43 to the
Read-Modify-Write Operations
To read a specific page or modify a few words, bytes, or bits in a page, use the RMW operations. A read
command copies the desired data from flash memory to a page buffer. You can then modify the
information in the buffer using MAP00 buffer read and write commands and issue another command to
write that information back to the memory.
The read-modify-write command operates on an entire page. This command is also useful for a copy type
operation, where most of a page is saved to a new location. In this type of operation, the NAND flash
controller reads the data, modifies a specified number of words in the page, and then writes the modified
page to a new location.
Note: Because the data is modified within the page buffer of the flash device, the NAND flash controller
ECC hardware is not used in RMW operations. Software must update the ECC during RMW
operations.
Altera Corporation
MAP10 Transfer Mode Commands
on page 13-11
register.
Data
register in the group. If it is set to 1, then the transfer mode becomes main
config
register.
Data
register.
Data
0x41 Spare
0x43 Main+spare
field to 2 and the
CMD_MAP
field to 2 and the
CMD_MAP
field to 2 and the
CMD_MAP
Resulting NAND Flash Controller
Mode
field to any block.
BLK_ADDR
field to the target block.
BLK_ADDR
field to the target
BLK_ ADDR
NAND Flash Controller
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cv_5v4
2016.10.28