User Manual

Introduction to the TriFlash with SD Interface
1-8 TriFlash with SD Interface Product Manual (Preliminary), Rev. 1.2 © 2002/2003 SANDISK CORPORATION
1.5.7.6. Read and Write Operations
The TriFlash supports two read/write modes as shown in Figure 1-3.
Memory
Sectors
Memory
Sectors
Memory
Sectors
Memory
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Memory
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Memory
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Memory
Sectors
Start
Address
(Read)
Start
Address
(Write)
Start
Address
(Read/Write)
Memory
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Memory
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Memory
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Memory
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Start
Address
Stop StopStart
ReadWrite
Single Block Mode Misalignment Error
Multiple Block Mode
Figure 1-3. Data Transfer Formats
Single Block Mode
In this mode the host reads or writes one data block in a pre-specified length. The data block transmission is
protected with 16-bit CRC, which is generated by the sending unit and checked by the receiving unit.
The block length, for read operations, is limited by the device sector size (512 bytes) but can be as small as a single
byte. Misalignment is not allowed. Every data block must be contained in a single physical sector.
The block length for write operations must be identical to the sector size and the start address aligned to a sector
boundary.
Multiple Block Mode
This mode is similar to the single block mode, but the host can read/write multiple data blocks (all have the same
length), which will be stored or retrieved from contiguous memory addresses starting at the address specified in the
command.
The operation is terminated with a stop transmission command.
Misalignment and block length restrictions apply to multiple blocks as well and are identical to the single block
read/write operations.