Reset and interrupt handling – Maxtor DIAMONDMAXTM PLUS 5120 92048D8 User Manual

Page 48

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HOST SOFTWARE INTERFACE

6 – 6

Reset and Interrupt Handling

Reset Handling

One of three different conditions may cause a reset: power on, hardware reset or software reset. All three
cause the interface processor to initialize itself and the Task File registers of the interface. A reset also causes a
set of the Busy bit in the Status register. The Busy bit does not clear until the reset clears and the drive
completes initialization. Completion of a reset operation does not generate a host interrupt.

Task File registers are initialized as follows:

Error

1

Sector Count

1

Sector Number

1

Cylinder Low

0

Cylinder High

0

Drive/Head

0

Interrupt Handling

The drive requests data transfers to and from the host by asserting its IRQ 14 signal. This signal interrupts the
host if enabled by bit 1 (IRQ enable) of the Fixed Disk Control register.

Clear this interrupt by reading the Status register, writing the Command register, or by executing a host
hardware or software reset.

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