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S3C6400X RISC MICROPROCESSOR
COMMAND MAPPING
There are four kinds of commands supported by the OneNand flash memory controller. These commands are
selected through the value of bits 23 and 22 of the incoming address. The command mapping determines the way
in which the lower 22 bits of the address will be used.
• " 00" = Map 00 Commands.
Map 00 commands are used to access a controller-selected buffer in the flash memory device including boot,
dataram 0 and dataram 1. The addressing will always begin at 0x0 and the memory controller will map that
address to the appropriate buffer. The user will know the maximum address of the buffer through the
boot_buffer_size and data_buffer_size registers.
In most cases, the buffer used will be the boot buffer, and the user will use this command to read data from this
buffer. However, Map 00 commands are also used in read/modify/write operations. When the read/modify/write
command sequence is followed, map 00 commands may be used to read or write any word in the buffer. The
memory controller will select dataram 0 or dataram 1 automatically. The selection is invisible to the command
requestor.
Address
Bits
31:24
23:22
21:17
16:1
0
• "01" = Map 01 Commands.
Map 01 commands are used for normal high-speed accesses to the memory array. The user can read and write
data to a particular page of the array by specifying the FBA and FPA for the command. Since the OneNAND flash
controller only supports page addresses (FSA must be set to 0), an entire page must be read or written at a time.
The actual number of commands used depends on the size of the data transfer. Even if multiple commands are
required, the same address must be used until the entire block has been transferred.
Each read or write data word will be 32-bits in size. The asynchronous buffers will separate the write data into two
16-bit words or concatenate the read data into one 32-bit word.
Table 7-2 Map 00 Address Mapping
Name
AHB_int_add
CMD_MAP
RESV
MEM_ADDR
BYTE
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.
Description
AHB Port Address
00 = Read or Write of XIP buffer
Reserved space
Buffer Address on the Memory Device
Must be set to zero
ONENAND CONTROLLER
7-5
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