Fujitsu MHW2040AC User Manual download pdf (Page 83)

5.2 Logical Interface

5.2.1 I/O registers

Communication between the host system and the device is done through input-

output (I/O) registers of the device.

These I/O registers can be selected by the coded signals, CS0-, CS1-, and DA0 to

DA2 from the host system. Table 5.2 shows the coding address and the function of

I/O registers.

Table 5.2 I/O registers

I/O registers

Read operation Write operation

Command block registers

L H L L L Data Data X’1F0’

L H L L H Error Register Features X’1F1’

L H L H L Sector Count Sector Count X’1F2’

L H L H H Sector Number Sector Number X’1F3’

L H H L L Cylinder Low Cylinder Low X’1F4’

L H H L H Cylinder High Cylinder High X’1F5’

L H H H L Device/Head Device/Head X’1F6’

L H H H H Status Command X’1F7’

L L X X X (Invalid) (Invalid) —

Control block registers

H L H H L Alternate Status Device Control X’3F6’

H L H H H — — X’3F7’

Notes:

1. The Data register for read or write operation can be accessed by 16 bit data

bus (DATA0 to DATA15).

2. The registers for read or write operation other than the Data registers can be

accessed by 8 bit data bus (DATA0 to DATA7).

3. When reading the Drive Address register, bit 7 is high-impedance state.

4. H indicates signal level High and L indicates signal level Low.

There are two methods for specifying the LBA mode. One method is to

specify the LBA mode with 28-bit address information, and the other is to

specify it with 48-bit address information (command of EXT system). If the

LBA mode is specified with 28-bit address information, the Device/Head,

Host I/O

address

DA0 DA1 DA2 CS1– CS0–

C141-E258 5-7

1 2 ... 78 79 80 81 82 83 84 85 86 87 88 ... 277 278

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Fujitsu MHW2040AC User Manual Page 83