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ATA-Disk Module

SST58SM008 / 016 / 024 / 032 / 048 / 064 / 096 / 128 / 192

SST58LM008 / 016 / 024 / 032 / 048 / 064 / 096 / 128 / 192

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3.1.2.9 Status & Alternate Status Registers (Read Only)

These registers return the ADM status when read by the host. Reading the Status register does clear a pending inter-

rupt while reading the Auxiliary Status register does not. The meaning of the status bits are described as follows:

Bit 7 (BUSY) The busy bit is set when the ADM has access to the command buffer and registers and

the host is locked out from accessing the command register and buffer. No other bits in

this register are valid when this bit is set to a 1.

Bit 6 (RDY)

RDY indicates whether the device is capable of performing ADM operations. This bit is

cleared at power up and remains cleared until the ADM is ready to accept a command.

Bit 5 (DWF)

This bit, if set, indicates a write fault has occurred.

Bit 4 (DSC)

This bit is set when the ADM is ready.

Bit 3 (DRQ)

The Data Request is set when the ADM requires that information be transferred either to

or from the host through the Data register.

Bit 2 (CORR) This bit is set when a Correctable data error has been encountered and the data has

been corrected. This condition does not terminate a multi-sector Read operation.

Bit 1 (IDX)

This bit is always set to 0.

Bit 0 (ERR)

This bit is set when the previous command has ended in some type of error. The bits in

the Error register contain additional information describing the error. It is recommended

that media access commands (such as Read Sectors and Write Sectors) that end with

an error condition should have the address of the first sector in error in the command

block registers.

3.1.2.10 Device Control Register (Write Only)

This register is used to control the ADM interrupt request and to issue a software Reset. This register can be writ-

ten to even if the device is BUSY. The bits are defined as follows:

Bit 7

This bit is an X (don’t care).

Bit 6

This bit is an X (don’t care).

Bit 5

This bit is an X (don’t care).

Bit 4

This bit is an X (don’t care).

Bit 3

This bit is ignored by the ADM.

Bit 2 (SW Rst) This bit is set to 1 in order to force the ADM to perform a software Reset operation. The

chip remains in Reset until this bit is reset to ‘0.’

Bit 1 (-IEn)

The Interrupt Enable bit enables interrupts when the bit is 0. When the bit is 1, interrupts

from the ADM are disabled. This bit is Reset to 0 at power on and Reset.

Bit 0

This bit is ignored by the ADM.

D7

D6

D5

D4

D3

D2

D1

D0

BUSY

RDY

DWF

DSC

DRQ

CORR

0

ERR

D7

D6

D5

D4

D3

D2

D1

D0

XXX

X1

SW Rst

-IEn

0