PC87306 datasheet(42/110 Pages) NSC

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40 FDC Command Set Description (Continued)

TABLE 4-9 SK Effect on the Read Data Command

Data Type

Sector Read

CM Bit (ST2)

Description of Results

Normal

Normal Termination

Deleted

No Further Sectors Read

Normal

Normal Termination

Deleted

Sector Skipped

TABLE 4-10 Result Phase Termination Values with No Error

Sector

Last

ID Information at Result Phase

Track

Head

Sector

BytesSector

EOT

S a 1NC

EOT

T a 1NC

EOT

S a 1NC

EOT

T a 1NC

EOT

S a 1NC

EOT

S a 1NC

EOT

T a 10

EOT e End of Track Sector Number from Command Phase

S e Sector Number last operated on by controller

NC e No Change in Value

T e Track Number programmed in Command Phase

TABLE 4-11 SK Effect on the Read Deleted Data Command

Data Type

Sector Read

CM Bit (ST2)

Description of Results

Normal

No Further Sectors Read

Deleted

Normal Termination

Normal

Sector Skipped

Deleted

Normal Termination

4110 Read Deleted Data Command

The Read Deleted Data command reads logical sectors

containing a Deleted Data AM from the selected drive and

makes the data available to the host mP This command is

identical to the Read Data command except for the setting

of the CM bit in ST2 and the skipping of sectors The effect

of SK on the Read Deleted Data command is summarized in

Table 4-11 See Table 4-10 for the state of the result bytes

for a Normal Termination of the command

Command Phase

MFM

IPS

DR1

DR0

Track Number

Drive Head Number

Sector Number

Bytes per Sector

End of Track Sector Number

Intersector Gap Length

Data Length

Execution Phase

Data read from disk drive is transferred

to system via DMA or Non-DMA modes

Result Phase

Status Register 0

Status Register 1

Status Register 2

Track Number

Head Number

Sector Number

Bytes per Sector

4111 Read ID Command

The Read ID command finds the next available Address

Field and returns the ID bytes (track head sector bytes per

sector) to the mP in the Result Phase There is no data

transfer during the Execution Phase of this command An

interrupt is generated when the Execution Phase is complet-

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