
Operations
When the next command requests to read the
6.4.1 Data buffer configuration
The drive has a 2 MB data buffer. The buffer is used by divided into three parts; for read/write commands, and for MPU work (see Figure 6.9).
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Figure 6.7 Data buffer configuration
The
6.4.2 Caching operation
Caching operation is performed only at issuance of the following commands. The device transfers data from the data buffer to the host system at issuance of following command if following data exist in the data buffer.
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All sectors to be processed by the command
A part of data including load sector to be processed by the command
When a part of data to be processed exist in the data buffer, remaining data are read from the medium and are transferred to the host system.
(1) Commands that are object of caching operation
Follow commands are object of caching operation.
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READ SECTOR (S)
READ MULTIPLE
READ DMA
When caching operation is disabled by the SET FEATURES command, no caching operation is performed.
(2) Data that are object of caching operation
Follow data are object of caching operation.