Specifications

ATAPI For Streaming Tape QIC-157 Rev B

The ATAPI Identify Device command shall not delay the transfer of the Identify Device data by

more than 200 ms after receipt of the command. When the command is issued, the device sets BSY,

sets up parameter information in the data buffer, and then sets DRQ and INTRQ.

Implementor's Note: All ASCII fields will be byte swapped to maintain compatibility with ATA. For

example, “This Example” would be written as “hTsiE axpmel”.

4.1.7.1. General Configuration Word (0)

Table 4-2 Identify Device Data - General Configuration (Word 0)

Bit

Byte

7/15 6/14 5/13 4/12 3/11 2/10 1/9 0/8

0 Removable CMD DRQ Type Reserved CMD Packet Size (00)

1 Protocol Type (10b) Reserved Device Type (01)

Bits 15-14 Protocol

Type

This field indicates the protocol in use by the Device.

0Xb = ATA

10b = ATAPI

11b = Reserved

Bit 13 Reserved This is reserved for future enhancement

Bits 12-8 Device

Type

This field indicates the Device type. The peripheral types are

described in Table 6-9 Peripheral Device Types on page 45.

Bit 7 Removable Indicates that the Device has removable media.

Bits 6-5 CMD DRQ

Type

This field indicates the command packet DRQ type used by this

Device.

00b = Microprocessor DRQ:

ATAPI Devices reporting Microprocessor DRQ assertion shall assert

DRQ within 3ms of receiving the A0h ATAPI Packet Command.

Implementor's Note: Devices reporting Microprocessor DRQ require

the Device Driver to poll for up to 3ms or accept the granularity of an

available timer tick. These issues may result in undesirable system

delays when used with multi-threaded OS Drivers.

01b = Interrupt DRQ:

ATAPI Devices reporting Interrupt DRQ assertion shall assert

INTRQ in conjunction with the assertion of the command packet

DRQ. These Devices shall assert DRQ within 10ms of receiving the

A0h ATAPI Packet Command.

10b = Accelerated DRQ:

ATAPI Devices reporting Accelerated DRQ assertion shall assert

DRQ within 50us of receiving the A0h ATAPI Packet Command.

11b = Reserved for future use.

Bits 4-2 Reserved This field is unique for each protocol and is reserved for future use.