HB288032MM1 Datasheet, PDF (14/80 Pages) Hitachi Semiconductor – MultiMediaCard 32 MByte

HB288032MM1
• READ_BLK_LEN
The data block length is computed as 2 . ^READ_BLK_LEN
Data Block Length
READ_BLK_LEN
0
1
......
11
12–15
Block length
2⁰ = 1 byte
2¹ = 2 bytes
......
2¹¹ = 2048 bytes
reserved
Remark
The block length might therefore be in the range 1, 2, 4...2048 bytes. This parameter defines the block
length if READ_BLK_PARTIAL is not set. If READ_BLK_PARTIAL is set this parameter contains the
maximum allowed value of the block length in bytes. All block lengths between one and this value are
permitted. The actual block size is programmed by the command SET_BLOCKLEN (CMD16). The
HB288032MM1 supports block lengths from 1 byte up to 2048 bytes. The parameter READ_BLK_LEN is
permanently assigned to the value 0x9.
• READ_BLK_PARTIAL
READ_BLK_PARTIAL defines whether partial block sizes can be used in block read and block write
commands. READ_BLK_PARTIAL = 0 means that only the block size defined by READ_BLK_LEN can
be used for block-oriented data transfers. READ_BLK_PARTIAL = 1 means that smaller blocks can be
used as well. The minimum block size will be equal to minimum addressable unit (one byte). The
HB288032MM1 supports partial block read. The parameter READ_BLK_PARTIAL is permanently
assigned to the value ‘1’.
• WRITE_BLK_MISALIGN
Defines if the data block to be written by one command can be spread over more than one physical blocks
of the memory device. The size of the memory block is defined in WRITE_BLK_LEN.
WRITE_BLK_MISALIGN is permanently assigned to the value ‘0’, signalling that crossing physical block
boundaries is not allowed.
• READ_BLK_MISALIGN
Defines if the data block to be read by one command can be spread over more than one physical block of
the memory device. The size of the data block is defined in READ_BLK_LEN. READ_BLK_MISALIGN
= 0 signals that crossing physical block boundaries is not allowed. READ_BLK_MISALIGN = 1 signals
that crossing physical block boundaries is allowed. The HB288032MM1 does not support read block
operations with boundary crossing. The parameter READ_BLK_MISALIGN is permanently assigned to
the value ‘0’.
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