Hitachi.comHitachi.us 
Hard disk drives
 
   
Deskstar 8
Electrical interface specifications

Models: DHEA-34331, 36481, 38451


Connectors

The DC power connector is designed to mate with AMP part 1-480424 (using AMP pins P/N 350078-4). Equivalent assignments are shown below, viewed from the end of the drive.
DC power connector
IDE connector

The drive uses single-ended drivers and receivers. The connector is designed to mate with 3M part 3417-7000 or equivalent.
AT/IDE connector
Notes:
  1. A/T = IDE
  2. It is intended that the drive should only be in electrical contact with the system chassis through the mounting holes. Other electrical contact may degrade error rate performance. As a result of this it is recommended that there should be no metal contact to the drive except at the mounting holes or the side rails into which the mounting holes are tapped.

Cabling

The maximum cable length from the host system to the drive, plus the circuit pattern length inside the host systems, must not exceed 18 inches (45.7 cm).

For higher data transfer application (>8.3 MB/sec) a consideration in system design is recommended to reduce cable noise and/or cross-talk, such as; shorter cable, bus termination, shielded cable, etc.


Signal definition
 
Pin Signal I/O Pin Signal I/O
01 -RESET I 02 GND
03 DD07 I/O 04 DD08 I/O
05 DD06 I/O 06 DD09 I/O
07 DD05 I/O 08 DD10 I/O
09 DD04 I/O 10 DD11 I/O
11 DD03 I/O 12 DD12 I/O
13 DD02 I/O 14 DD13 I/O
15 DD01 I/O 16 DD14 I/O
17 DD00 I/O 18 DD15 I/O
19 GND (20) KEY
21 DMARQ O 22 GND
23 -DIOW * I 24 GND
25 -DIOR * I 26 GND
27 IORDY * O 28 CSEL I
29 -DMACK I 30 GND
31 INTRQ O 32 -HIOCS16 O
33 DA01 I 34 -PDIAG I/O
35 DA00 I 36 DA02 I
37 -CSO I 38 -CS1 I
39 -DASP I/O 40 GND

Notes:
  1. "O" designates an output from the drive.
  2. "I" designates an input from the drive.
  3. "I/O" designates an input/output.
  4. "*" these signal lines are redifined during the Ultra DMA protocol to provide special functions as detailed in the table below.
    Ultra DMA special functions
Interface

The interface conforms to the working document of information technology - AT attachment - 3 interface (ATA-3) revision 6 dated October 26 1995 with following deviations.

ICRCE (Interface CRC error)
Bit 7 of Error Rigister is supported as Interface CRC Error bit. This bit will be set if a CRC error has occurred on the data bus during an ULTRA-DMA transfer.

Check power mode
Check Power Mode command returns FFh to the sector count register when the drive is in idle mode. This command does not support 80h as the return value.

Sleep mode
During sleep mode the drive will be activated by any command, including, but not limited to, a soft reset.

Hard reset
Hard reset response is identical to a soft reset response with the following exception: in a hard reset, the drive goes through the Master/Slave handshake to determine if a slave is present, in a soft reset this handshake does not occur. In a hard reset the Master drive looks at the DASP line to determine if it is asserted indicating a Slave is present. The Master drive also checks the PDIAG line to see if the Slave has passed its internal diagnostics.

Registers (primary channel addresses)

Address Input register Output register
1F0h data data
1F1h error  features
1F2h sector count sector count
1F3h
sector number
*LBA bits 0-7
sector number
*LBA bits 0-7
1F4h
cylinder low
*LBA bits 8-15
cylinder low
*LBA bits 8-15
1F5h
cylinder high
*LBA bits 16-23
cylinder high
*LBA bits 16-23
1F6h
drive/head
*LBA bits 24-27
drive/head
*LBA bits 24-27
1F7h status command
3F6h alternate status device control
3F7h drive address not used

The host uses the register interface to communicate to and from the drive. The registers are accessed through the host port addresses shown. The host should not read or write any registers when the Status Register BSY bit = 1.

Note: *Meaning of register contents when LBA addressing mode used.
 




   Terms of Use | Privacy Policy | Contact Us