Fujitsu MHZ2250BJ Manuel d'utilisateur télécharger pdf (Page 87)

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

Data Port

Error Features

Sector Count (exp) Sector Count Sector Count (exp) Sector Count

Sector Number (exp) Sector Number Sector Number (exp) Sector Number

Cylinder Low (exp) Cylinder Low Cylinder Low (exp) Cylinder Low

Cylinder High (exp) Cylinder High Cylinder High (exp) Cylinder High

Device / Head

Status Command

Control Block registers

Alternate Status Device Control

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-E280 5-13

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Fujitsu MHZ2250BJ Manuel d'utilisateur Page 87