Input/Output Stream Descriptor x FIFO Limit (ISD0FIFOL) – Offset 94 - 1.2 - ID:615146 | Intel® 400 Series Chipset On-Package Platform Controller Hub

Intel® 400 Series Chipset On-Package Platform Controller Hub

Online Register Database

ID	Date	Version	Classification
615146	08/09/2019	1.2	Public

Input/Output Stream Descriptor x FIFO Limit (ISD0FIFOL) – Offset 94

NOTE: This register applies to the following input and output streams at the corresponding offsets:

Input stream 0: offset 94h

Input stream 1: offset B4h

Input stream 2: offset D4h

Input stream 3: offset F4h

Input stream 4: offset 114h

Input stream 5: offset 134h

Input stream 6: offset 154h

Input stream 7: offset 294h

Input stream 8: offset 2B4h

Input stream 9: offset 2D4h

Input stream 10: offset 2F4h

Input stream 11: offset 314h

Input stream 12: offset 334h

Input stream 13: offset 354h

Input stream 14: offset 374h

Output stream 0: offset 174h

Output stream 1: offset 194h

Output stream 2: offset 1B4h

Output stream 3: offset 1D4h

Output stream 4: offset 1F4h

Output stream 5: offset 214h

Output stream 6: offset 234h

output stream 7: offset 254h

Output stream 8: offset 274h

Output stream 9: offset 394h

Output stream 10: offset 3B4h

Output stream 11: offset 3D4h

Output stream 12: offset 3F4h

Output stream 13: offset 414h

Output stream 14: offset 434h

Bit Range	Default	Access	Field Name and Description
14	0b	RW/L	Granularity (GNL) Granularity associated with LMT field definition. The LMT value needs to be multiplied with 125 us or 1 ms to get the access limit in time domain. 0 = 125 us 1 = 1 ms This bit is locked if GCAP2.EEAC = 0 (thus appear to be RO).
13:0	0000h	RW/L	FIFO Limit (FIFOL) Indicate how far the media player / application intend to process ahead, in units of time. HW can extend the effective FIFO size to fetch (for output stream) or evict (for input stream) more data in the cyclic buffer beyond the minimum FIFO size advertised in FIFOS register, up to this access limit. Need to multiply with the granularity (125 us vs. 1 ms) as defined in GNL bit, to get the actual processing ahead time. 0 = Disabled (FIFOS is the limit) 0001h 3FFFh = 1 16383 units When value ) 0 (enabled), setting FIFOLC bit will trigger HW to evaluate the access limit change and update effective FIFO size (depending on the capability supported). SW shall make sure the FIFOL field is not changed in the progress of access limit change sequence. This bit is locked if GCAP2.EEAC = 0 (thus appear to be RO).

Bit Range

Default

Access

Field Name and Description

RW/L

Granularity (GNL)

Granularity associated with LMT field definition. The LMT value needs to be

multiplied with 125 us or 1 ms to get the access limit in time domain.

0 = 125 us

1 = 1 ms

This bit is locked if GCAP2.EEAC = 0 (thus appear to be RO).

13:0

0000h

RW/L

FIFO Limit (FIFOL)

Indicate how far the media player / application intend to process ahead, in

units of time. HW can extend the effective FIFO size to fetch (for output

stream) or evict (for input stream) more data in the cyclic buffer beyond

the minimum FIFO size advertised in FIFOS register, up to this access limit.

Need to multiply with the granularity (125 us vs. 1 ms) as defined in GNL bit,

to get the actual processing ahead time.

0 = Disabled (FIFOS is the limit)

0001h 3FFFh = 1 16383 units

When value ) 0 (enabled), setting FIFOLC bit will trigger HW to evaluate the

access limit change and update effective FIFO size (depending on the capability

supported). SW shall make sure the FIFOL field is not changed in the progress

of access limit change sequence.

This bit is locked if GCAP2.EEAC = 0 (thus appear to be RO).