17 set multiple mode (c6h), 18 read dma (c8h/c9h) – Toshiba MK6017MAP User Manual

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10.8.17 Set Multiple Mode (C6h)

COMMAND CODE

1 1 0 0 0 1 1 0

REGISTER

REGISTER SETTING

NORMAL COMPLETION

DR

drive no.

no change

CY

no

change

HD

no

change

SN

no

change

SC

The number of sectors / block

no change

FT

no

change

This command enables the drive to perform Read and Write Multiple operations and sets the block count for
these commands.

The Sector Count Register is loaded with the number of sectors per block. The drive supports 1,2,4,8 or16
sectors per block.

Upon receipt of the command, the drive sets BSY=1 and checks the content of Sector Count Register.

If the Sector Count Register contains a valid value and the block count is supported, the value is loaded for
all subsequent Read Multiple and Write Multiple commands. And these commands are enabled to be
executed. If a block count is not supported , this command shall be terminated with the report of an Aborted
Command error , and Read Multiple and Write Multiple commands are disabled.

If the Sector Count Register contains 0 when the command is issued, Read Multiple and Write Multiple
commands are disabled.

In case of software reset, the result depends on the setting of Set Feature command. If FT=66h, the mode
is not changed. If FT = CCh, the mode reverts to power on default (16 sectors).

10.8.18 Read DMA (C8h/C9h)

COMMAND CODE

1 1 0 0 1 0 0 X

REGISTER

REGISTER SETTING

NORMAL COMPLETION

DR

drive no.

no change

CY

starting cylinder

last possible

HD

starting head

last possible

SN

starting sector

last possible

SC

no. of sector to read

00H

FT

no

change

LBA

staring address

last address

This command is basically identical to Sector command except following features.

Host initialize slave-DMA channel before issuing command.
- Data transfer is initiated by DMARQ and handled by slave-DMA channel in the host.
- Drive issues only one interrupt at the completion of each command to show the status is valid after data
transfer.

During DMA transfer phase, either BSY or DRQ is set to 1.
When a command is completed, CY, HD, SN register (LBA register) shows the sector transferred the latest.

If the drive detects unrecoverable error, the drive terminate the command and CY, HD, SN register (LBA
register) shows the sector where error occurred.

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