Device Capabilities (DCAP) – Offset 44 - 001 - ID:834576 | Intel® 800 Series Chipset Family Platform Controller Hub (PCH), Volume 2

Intel® 800 Series Chipset Family Platform Controller Hub (PCH), Volume 2

ID	Date	Version	Classification
834576	10/10/2024	001	Public

Device Capabilities (DCAP) – Offset 44

This is the Device Capabilities registers. Refer description for each individual field below for more details of the register functionality.

Bit Range	Default	Access	Field Name and Description
31:29	0h	RO	Reserved (RSVD_M) Reserved.
28	0h	RO	Function Level Reset Capable (FLRC) Not supported in Root Ports
27:26	0h	RO	Captured Slot Power Limit Scale (CSPS) Not supported.
25:18	0h	RO	Captured Slot Power Limit Value (CSPV) Not supported.
17:16	0h	RO	Reserved
15	1h	RO	Role Based Error Reporting (RBER) Indicates that this device implements the functionality defined in the Error Reporting ECN as required by the PCI Express 1.1 spec.
14	0h	RO	Reserved. On previous version of the specification this was Power Indicator Present (PIP) Reserved
13	0h	RO	Reserved. On previous version of the specification this was Attention Indicator Present (AIP) Reserved
12	0h	RO	Reserved. On previous version of the specification this was Attention Button Present (ABP) Reserved
11:9	0h	RO	Endpoint L1 Acceptable Latency (E1AL) Reserved for root ports.
8:6	0h	RO	Endpoint L0s Acceptable Latency (E0AL) Reserved for Root port.
5	0h	RW/O	Extended Tag Field Supported (ETFS) The Root Port never needs to initiate a transaction as a Requester with the Extended Tag bits being set. This bit does not affect the root ports ability to forward requests as a bridge as the root port always supports forwarding requests with extended tags. Register Attribute: Static.
4:3	0h	RO	Phantom Functions Supported (PFS) No phantom functions supported
2:0	1h	RW/L	Max Payload Size Supported (MPS) Max Payload Size of up to 256B is supported. Programming this field to any values other than 128B or 256B max payload size will result in aliasing to 128B max payload size. 000b: 128 bytes max payload size. 001b: 256 bytes max payload size. 010b: 512 bytes max payload size. 011b: 1024 bytes max payload size. 100b: 2048 bytes max payload size. 101b: 4096 bytes max payload size. 110b: Reserved. 111b: Reserved. This field applies only to the PCIe link interface. A separate register is defined for the IOSF interface. Register Attribute: Static. This register is Read-Only if LPCRE.IPCL field is set