Samsung S3C6400X User Manual page 139

S3C6400X RISC MICROPROCESSOR
- Verify Read Operations
Multi-block erases must be verified through a verify read command. This command operates serially and verifies
one block at a time. Each block of the multi-block erase must be verified! An interrupt (Ers_Fail) will be triggered if
the block does not verify.
The verify read command used is determined by the type of transaction on the AHB bus (read or write) and the
low byte of the datain bus.
Address
[23:22] = 10
DFS_DBS and FBA are used.
FPA and FSA are unused for Erase Verify
Operations and must be cleared.
- Pipeline Read-Ahead or Write-Ahead Operations
The OneNand flash controller supports pipeline read-ahead and write-ahead operations. However, the memory
device may have limited support for this function. If pipelined read-ahead or write-ahead is not supported, these
commands will be ignored.
The pipeline read-ahead function allows for a continuous reading of the memory, even when the read request has
not been issued to the controller. The pipeline read-ahead function utilizes a set of registers in the controller to
hold the specified pages of data starting at a given address. The group of reads is accessed as a continuous
series of pages. By pulling this data into the memory controller prior to the actual read request being issued, the
memory controller is able to reduce latency on returning read data to the AHB interface.
The pipeline write-ahead function allows for the AHB interface to accept write data, even when the write request
has not been issued to the controller. The pipeline write-ahead function utilizes a set of registers in the controller
to hold the specified pages of data starting at a given address. The data is accepted as a continuous series of
pages. By pulling this data into the memory controller prior to the actual write request being issued, the memory
controller is able to reduce latency on writing the data to the flash.
Note that the buffers used for pipelined read-ahead and write-ahead commands are the same. Data that is pre-
read must be read out to the AHB interface before proceeding. Data that is pre-written must be written to flash
before proceeding.
Address Cmd
Type
[23:22] = 10 Write
DFS_DBS, FBA,
FPA, and FSA
are used.
Note that a Pipelined Read-Ahead or Write-Ahead for a single area must request at least 2 pages.
Cmd
Type
Write
Datain Function
0x4WPP Save this address as the initial address for the read/write. For
reads, "W"=0 and this will initiate a copy of PP pages from the
memory to memory controller. For writes, "W"=1 and this will
initiate acceptance of PP pages from the AHB interface to the
memory controller.
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
Datain Function
0x15 Save the block address for an erase
verification and initiate the verify
command.
ONENAND CONTROLLER
7-9