Outline Of The Shadow Block Register; Table 5.3 Shadow Block Register - Fujitsu MHW2120BK Maintenance Manual

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.
Sector Count (exp)
Sector Number (exp)
Cylinder Low (exp)
Cylinder High (exp)
Alternate Status
Note: Each of the Sector Count, Sector Number, Cylinder Low, and Cylinder
High fields has a higher-order field used for issuing the Ext command.
The fields are called Sector Count exp, Sector Number exp, Cylinder
Low exp, and Cylinder High exp, respectively. For information on
writing data to these fields, see "Device Control Field."
C141-E261

Table 5.3 Shadow Block Register

Command Block registers
Read
Data Port
Error
Sector Count
Sector Number
Cylinder Low
Cylinder High
Device / Head
Status
Control Block registers
Write
Features
Sector Count (exp)
Sector Number (exp)
Cylinder Low (exp)
Cylinder High (exp)
Command
Device Control
5.2 Logical Interface
Sector Count
Sector Number
Cylinder Low
Cylinder High
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