Hitachi HDS723020BLA642 manual Read DMA Ext 25h, Read DMA Ext Command 25h

7K200 SATA OEM Specification

14.14Read DMA Ext (25h)

	Command Block Output Registers																								Command Block Input Registers
	Register					7		6				5		4			3		2			1	0		Register					7			6	5		4	3			2	1			0
	Data Low				-		-				-		-			-		-			-		-		Data Low					-		-		-		-	-		-		-		-
	Data High				-		-				-		-			-		-			-		-		Data High					-		-		-		-	-		-		-		-
	Feature		Current			-		-				-		-			-		-			-	-		Error									...See Below...
			Previous			-		-				-		-			-		-			-	-
	Sector Count		Current			V			V			V		V			V		V			V	V		Sector Count			HOB=0		-			-	-		-	-			-	-			-
			Previous			V			V			V		V			V		V			V	V					HOB=1		-			-	-		-	-			-	-			-
	LBA Low		Current			V			V			V		V			V		V			V	V		LBA Low			HOB=0		V			V	V		V	V			V	V			V
			Previous			V			V			V		V			V		V			V	V					HOB=1		V			V	V		V	V			V	V			V
	LBA Mid		Current			V			V			V		V			V		V			V	V		LBA Mid			HOB=0		V			V	V		V	V			V	V			V
			Previous			V			V			V		V			V		V			V	V					HOB=1		V			V	V		V V V					V			V
	LBA High		Current			V			V			V		V			V		V			V	V		LBA High			HOB=0		V		V		V		V	V		V		V		V
			Previous			V			V			V		V			V		V			V	V					HOB=1		V			V	V		V	V			V	V			V
	Device				-		1				-		-			-		-			-		-		Device					-		-		-		-	-		-		-		-
	Command				0		0				1		0			0		1			0		1		Status									...See Below...
				Error Register																									Status Register
7		6	5	4	3					2					1					0				7		6	5		4		3				2			1				0
	CRC	UNC	0	IDN	0				ABT					T0N					AMN					BSY		RDY	DF		DSC	DRQ				COR			IDX				ERR
	V	V	0	V	0						V				0					0				0		V	0		V		-				0			0				V

Table 69 Read DMA Ext Command (25h)

The Read DMA Ext command reads one or more sectors of data from disk media, then transfers the data from the device to the host.

The sectors are transferred through the Data Register 16 bits at a time.

The host initializes a slave-DMA channel prior to issuing the command. The data transfers are qualified by DMARQ and are performed by the slave-DMA channel. The device issues only one interrupt per command to indicate that data transfer has terminated and status is available.

If an uncorrectable error occurs, the read will be terminated at the failing sector.

Output Parameters To The Device

Sector Count Current	The number of sectors to be transferred low order, bits (7:0).
Sector Count Previous	The number of sectors to be transferred high order, bits (15:8). If 0000h in the Sector
	Count register is specified, then 65,536 sectors will be transferred.
LBA Low Current	LBA (7:0)
LBA Low Previous	LBA (31:24)
LBA Mid Current	LBA (15:8)
LBA Mid Previous	LBA (39:32)
LBA High Current	LBA (23:16)
LBA High Previous	LBA (47:40)
Input Parameters From The	Device
LBA Low (HOB=0)	LBA (7:0) of the address of the first unrecoverable error.
LBA Low (HOB=1)	LBA (31:24)of the address of the first unrecoverable error.
LBA Mid (HOB=0)	LBA (15:8)of the address of the first unrecoverable error.
LBA Mid (HOB=1)	LBA (39:32)of the address of the first unrecoverable error.
LBA High (HOB=0)	LBA (23:16)of the address of the first unrecoverable error.
LBA High (HOB=1)	LBA (47:40)of the address of the first unrecoverable error.

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