CHAPTER 3 Data Format
3.1Data Space
3.2Logical Data Block Addressing
3.3Defect Management
This chapter explains data space definition, logical data block addressing, and defect management on the IDD.
3.1Data Space
The IDD manages the entire data storage area divided into the following three data spaces.
•User space: Storage area for user data
•Internal test space: Reserved area for diagnostic purposes
•System space: Area for exclusive use of IDD itself
The user space allows a user access by specifying data. These space can be accessed with the logical data block addressing method described in Section 3.2. The internal test space is used by Read/write test of
3.1.1Cylinder configuration
The IDD allocates cylinders to the user space, Internal test space, and system space. Figure 3.1 is the cylinder configuration.
Spare areas (alternate areas) for defective sectors are provided in the user space. Several sectors in the last track of one cell and several cell (alternate cylinders) in the user space are allocated as alternate areas according to the user's assignment (MODE SELECT command). See Subsection 3.1.2 for details.