Specifications

ATAPI For Streaming Tape QIC-157 Rev B

Table 4-6 Feature Number Description for Set Feature Command

Feature Number Data Transfer Mode. Mode contained in Sector Count Register Default Setting

03h Value in Sector

Count Register

Definition

PIO & DMA Mode 0

00000 00x PIO Default Transfer Mode

00001 xxx PIO Flow Control Transfer mode x

00010 xxx Single Word DMA mode x

00100 xxx Multi-Word DMA mode x

00011 xxx Reserved (For Pseudo DMA mode)

If a Device that supports this specification receives a Set Feature command with a Set Transfer

Mode parameter and a Sector count Register value of 00000 000, it shall set its default PIO transfer

mode.

If a Device that supports this specification receives a Set Feature command with a Set Transfer

Mode parameter and a Sector Count Register value of 00000 001 and the Device supports disabling

of IORDY, then the Device shall set its default PIO transfer mode and disable IORDY.

4.1.8.2. Disable Reverting to Power On Defaults (66h)

A setting of 66h allows settings of greater than 80h that may have been modified since power on to

remain at the same setting after a software reset. At power on, or after a hardware reset, the default

mode is the same as that represented by values greater than 80h.

4.1.8.3. Enable Reverting to Power On Defaults (CCh)

A setting of CCh shall cause the Device to revert back to the default for settings of greater than 80h,

which may have been modified since power on, after a software reset.

4.1.9. Sleep

This command is the only way to cause the Device to enter Sleep Mode. The Device is spun down,

and when it is stopped, BSY is cleared, an interrupt is generated, and the interface becomes

inactive.

The only way to recover from Sleep mode is with a software reset or a hardware reset.

NOTE: The use of hardware reset to recover from Sleep mode may be incompatible with continued

operation of the Host system.

A Device shall not power on in Sleep Mode nor remain in Sleep Mode following a reset sequence.

If the Device reduced power, the reduce power sequence is not executed.

4.1.10. Standby Immediate

This command causes the Device to enter the Standby Mode. The Device may return the interrupt

before the transition to Standby Mode is completed. If the Device has already reduced power, the

reduce power sequence is not executed.

For Standby immediate the Device may return the interrupt before the transition to Standby Mode is

completed.