Toshiba MK6017MAP manual Read Sector 20h/21h, Read Long6 22h/23h, Write Sector 30h/31h

360014937

10.8.4 Read Sector			(20h/21h)
	COMMAND CODE			0 0 1 0 0 0 L 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

Setting BSY bit, the drive will seek to the target cylinder if the head is not on target track ( implied seek ), select the head and begin to read the number of sector defined in SC register ( 1-256 ) starting from the target sector. After finding ID of target sector and having 1 sector of data read into the buffer RAM, the drive sets DRQ in status register and generates interrupt to report to the host that the drive is ready to transfer the next data.

In case of multi-sector transfer, DRQ bit is reset and BSY is set after 1 sector transfer to prepare for the next sector transfer.

An uncorrectable data can also be transferred but the subsequent operation will terminate at the cylinder, head, and sector (or LBA) position in the TASK FILE register. When a sector is ready to be read by the host, an interrupt is issued. After the last sector is read by the host, no interrupt is issued at the end of a command.

10.8.5 Read Long6 (22h/23h)

If L bit =1, this command returns the requested data and associated ECC information . The data field transfer is 16 bits wide, but the ECC information is accepted in only one byte (8 bits) at a time. Long command is valid only for single sector transfer (SC=01).

10.8.6 Write Sector			(30h/31h)
	COMMAND CODE			0 0 1 1 0 0 L X	REGISTER
		REGISTER SETTING			NORMAL COMPLETION
	DR		drive no.		no change
	CY		starting cylinder		last possible
	HD		starting head		last possible
	SN		starting sector		start sector
	SC		no. of sector to write		00H
	FT				no change
	LBA		starting address		last possible

The drive seeks to the target cylinder and selects the head and begins to write to the number of sectors defined in SC register (1-256) starting from the target sector. DRQ in status register is set as soon as the command register is written and the buffer RAM receives the data transferred from the host . After 1 sector is transferred to the buffer RAM, the drive resets DRQ, sets BSY and begins write operation. In case of multi-sector transfer, it sets DRQ bit, resets BSY and generates Interrupt to inform host that it is ready to transfer the next 1 sector of data. The drive will seek to the target cylinder if the head is not on the target track (implied seek). After transferring the last data in the buffer, it resets BSY and issues an interrupt.

6ATA/ATAPI-4 defines this command as Vendor specific. The drive supports this command to maintain ATA-3, and the previous models compatibility. User is recommended not to use this command.

Copyright © 2000 Toshiba corporation. All rights reserved.

- 561 -