Specifications

ATAPI For Streaming Tape QIC-157 Rev B

1. Host Sets and then clears SRST.

2. Master Device sets Busy, clears DASP & PDIAG and waits up to 3ms for Slave to assert DASP.

3. Slave Device also sets Busy, clears DASP & PDIAG and within 1ms asserts DASP.

4. Master Device waits up to 31s for PDIAG to be asserted.

5. Slave Device deasserts Busy and asserts PDIAG within 30s.

6. Master Device clears Busy.

7. Slave Device deasserts DASP after next command or after 31s.

3.4. Physical Connection

The ATAPI Devices are selected by the Address field in the Drive Select Register. When a single

Device is attached to the interface it shall be set as Device 0. When the ATAPI Device is attached

along with an ATA Mass Storage Drive, the ATAPI Device will be set as Device 1 and respond as a

Slave.

Table 3-1 Preferred Device Connection

Primary Cable Secondary Cable

Master

Slave

Master Slave Notes

ATA Drive Normal single cable

ATAPI Device Normal single cable

ATA Drive ATAPI Device Single cable with

Streaming Tape

ATAPI Device ATAPI Device Two ATAPI Devices on

Same Cable.

ATA Drive ATA Drive Two Drives on one cable

ATA Drive ATAPI Device One Drive and Streaming

Tape with two cables

ATA Drive ATA Drive ATAPI Device ATAPI Device Two Drives and two

ATAPI Devices

ATA Drive ATA Drive ATAPI Device Two Drives and Streaming

Tape with two cables

ATA Drive ATA Drive ATA Drive ATAPI Device Three Drives and Tape

Device with two cables

3.5. Register Mapping

Communication to or from the Device is through I/O Registers that route the input or output data to

or from registers (selected) by a code on signals from the Host (CS1FX-, CS3FX-, DA2, DA1,

DA0, DIOR- and DIOW-).

The ATAPI Device shall be capable of either Master or Slave operation.