AT INTERFACE DESCRIPTION

Pin Description Table

PIN NAME

PIN

I/O

SIGNAL NAME

SIGNAL DESCRIPTION

 

 

 

 

 

RESET -

01

I

Host Reset

Reset signal from the host system. Active during power up and inactive after.

 

 

 

 

 

DD0

17

I/O

Host Data Bus

16 bit bi-directional data bus between host and drive. Lower 8 bits used for

 

 

 

 

register and ECC byte transfers. All 16 bits used for data transfers.

DD1

15

I/O

 

 

DD2

13

I/O

 

 

DD3

11

I/O

 

 

DD4

09

I/O

 

 

DD5

07

I/O

 

 

DD6

05

I/O

 

 

DD7

03

I/O

 

 

DD8

04

I/O

 

 

DD9

06

I/O

 

 

DD10

08

I/O

 

 

DD11

10

I/O

 

 

DD12

12

I/O

 

 

DD13

14

I/O

 

 

DD14

16

I/O

 

 

DD15

18

I/O

 

 

DMARQ

21

O

DMA Request

This signal is used with DMACK for DMA transfers. By asserting this signal, the

 

 

 

 

drive indicates that data is ready to be transfered to and from the host.

DIOW -

23

I

Host I/O Write

Rising edge of Write strobe clocks data from the host data bus to a register on

STOP

 

 

 

the drive.

DIOR -

25

I

Host I/O Read

Read strobe enables data from a register on the drive onto the host data bus.

HDMARDY

 

 

 

DMA ready during UltraDMA data in bursts.

-

 

 

 

Data strobe during UltraDMA data out bursts.

HSTROBE

 

 

 

 

IORDY

27

O

I/O Channel Ready

This signal may be driven low by the drive to insert wait states into host I/O

DDMARDY

 

 

 

cycles.

-

 

 

 

DMA ready during UltraDMA data out bursts.

DSTROBE

 

 

 

Data strobe during UltraDMA data in bursts.

CSEL

28

 

Cable Select

Used for Master/Slave selection via cable. Requires special cabling on host

 

 

 

 

system and installation of Cable Select jumper.

DMACK -

29

I

DMA Acknowledge

This signal is used with DMARQ for DMA transfers. By asserting this signal, the

 

 

 

 

host is acknowledging the receipt of data or is indicating that data is available.

INTRQ

31

O

Host Interrupt

Interrupt to the host asserted when the drive requires attention from the host.

 

 

 

Request

 

IOCS16

32

 

Device 16 bit I/O

Obsolete

 

 

 

 

 

PDIAG -

34

I/O

Passed Diagnostic

Output by drive when in Slave mode; Input to drive when in Master mode.

 

 

 

 

 

DA0

35

I

Host Address Bus

3 bit binary address from the host to select a register in the drive.

 

 

 

 

 

DA1

33

I

 

 

 

 

 

 

 

DA2

36

I

 

 

 

 

 

 

 

CS0 -

37

I

Host Chip Select 0

Chip select from the host used to access the Command Block registers in the

 

 

 

 

drive. This signal is a decode of I/O addresses 1F0 - 1F7 hex.

CS1 -

38

I

Host Chip Select 1

Chip select from the host used to access the Control registers in the drive. This

 

 

 

 

signal is a decode of I/O addresses 3F6 - 3F7 hex.

DASP -

39

I/O

Drive Active/Drive

Time-multiplexed, open collector output which indicates that a drive is active, or

 

 

 

1 Present

that

 

 

 

 

device 1 is present.

GND

02

N/A

Ground

Signal ground.

 

 

 

 

 

 

19

 

 

 

 

 

 

 

 

 

22

 

 

 

 

 

 

 

 

 

24

 

 

 

 

 

 

 

 

 

26

 

 

 

 

 

 

 

 

 

30

 

 

 

 

 

 

 

 

 

40

 

 

 

 

 

 

 

 

KEY

20

N/A

Key

Pin used for keying the interface connector.

 

 

 

 

 

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Maxtor 96147H8, 93073H4, 91536H2, 94610H6, 92305H3 Pin Description Table, PIN Name Signal Name Signal Description