5.2 Logical Interface
5.2.2 Outline of the Shadow Block Register
Each transport layer in the host system and device has a block register, which is called a Shadow Block Register in the host system, and a Block Register in the device.
These registers are used when the host system issues a command to the device.
Table 5.3 Shadow Block Register
Command Block registers
Read |
| Write |
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| Data Port |
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Error |
| Features |
| ||
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|
Sector Count (exp) |
| Sector Count | Sector Count (exp) |
| Sector Count |
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|
|
|
|
Sector Number (exp) |
| Sector Number | Sector Number (exp) |
| Sector Number |
|
|
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Cylinder Low (exp) |
| Cylinder Low | Cylinder Low (exp) |
| Cylinder Low |
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|
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Cylinder High (exp) |
| Cylinder High | Cylinder High (exp) |
| Cylinder High |
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|
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|
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| Device / Head |
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|
|
| |||
Status |
| Command | |||
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| |
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| Control Block registers |
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Alternate Status | Device Control | ||||
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Note: Each of the Sector Count, Sector Number, Cylinder Low, and Cylinder High fields has a