Host to Device FIS - FIS Type (27h)

Host to Device FIS:

		31		30	29	28	27	26	25	24		23	22	21	20	19	18	17	16	15	14		13		12		11	10	9	8	7	6	5	4	3	2	1	0
	0		Features(7:0)								Command									C		R		R		R	PM Port				FIS Type (27h)
	1		Device								LBA(23:16)									LBA(15:8)											LBA(7:0)
	2		Features(15:8)								LBA(47:40)									LBA(39:32)											LBA(31:24)
	3		Control								ICC									Count(15:8)											Count(7:0)

FIS Type - Set to a value of 27h. Defines the rest of the FIS fields. Defines the length of the FIS as five Dwords.

C - This bit is set to one when the register transfer is due to an update of the Command register. The bit is cleared to zero when the register transfer is due to an update of the Device Control register. Setting C bit to one and SRST bit to one in the Device Control Field is invalid and results in indeterminate behavior.

Command - Contains the contents of the Command register of the Shadow Register Block.

LBA(7:0) - Contains the contents of the LBA Low register of the Shadow Register Block.

Control - Contains the contents of the Device Control register of the Shadow Register Block.

LBA(15:8) - Contains the contents of the LBA Mid register of the Shadow Register Block.

LBA(39:32) – Contains the contents of the expanded address field of the Shadow Register Block

LBA(23:16) - Contains the contents of the LBA High register of the Shadow Register Block.

LBA(47:40) – Contains the contents of the expanded address field of the Shadow Register Block

Device - Contains the contents of the Device register of the Shadow Register Block.

Features(7:0) - Contains the contents of the Features register of the Shadow Register Block.

Features(15:8) – Contains the contents of the expanded address field of the Shadow Register Block

PM Port – When an endpoint device is attached via a Port Multiplier, specifies the device port address that the FIS should be delivered to. This field is set by the host.

R – Reserved – shall be cleared to zero.

Count(7:0) - Contains the contents of the Sector Count register of the Shadow Register Block.

Count(15:8) – Contains the contents of the expanded address field of the Shadow Register Block

LBA(7:0) - Contains the contents of the LBA Low register of the Shadow Register Block.

LBA(31:24) – Contains the contents of the expanded address field of the Shadow Register Block.

ICC - Isochronous Command Completion (ICC) contains a value is set by the host to inform device of a time limit. If a command does not define the use of this field, it shall be reserved.