Intel® Core™ Ultra Processors for H-series and U-series Platforms SOC I/O Registers
Device Capabilities Register (DEVCAP) – Offset 84
Bit Range | Default | Access | Field Name and Description |
---|---|---|---|
31:28 | 0h | RO | RESERVED (RSVD) RESERVED |
27:26 | 0h | RO | Captured Slot Power Limit Scale (CSPLS) This register is applicable to upstream port only. Not supported hardwired to 0 |
25:18 | 0h | RO | Captured Slot Power Limit Value (CSPLV) This register is applicable to upstream port only. Not supported hardwired to 0 |
17:15 | 0h | RO | RESERVED (RSVD_1) RESERVED |
14 | 0h | RO | Power Indicator Present (PIP) This bit, when set, indicates that a Power Indicator is implemented on the card or module. Not supported hardwired to 0 |
13 | 0h | RO | Attention Indicator Present (AIP) This bit, when set, indicates that an Attention Indicator is implemented on the card or module. Not supported hardwired to 0 |
12 | 0h | RO | Attention Button Present (ABP) This bit when set indicates that an Attention Button is implemented on the card or module. Not supported hardwired to 0 |
11:9 | 7h | RW/O | Endpoint L1 Acceptable Latency (EPL1AL) This field indicates the acceptable latency that an Endpoint can withstand due to the transition from L1 state to the L0 state. It is essentially an indirect measure of the Endpoint's internal buffering. Power management software uses the reported L1 Acceptable Latency number to compare against the L1 Exit Latencies reported (see below) by all components comprising the data path from this Endpoint to the Root Complex Root Port to determine whether ASPM L1 entry can be used with no loss of performance. |
8:6 | 7h | RW/O | Endpoint L0s Acceptable Latency (EPL0AL) This field indicates the acceptable total latency that an Endpoint can withstand due to the transition from L0s state to the L0 state. It is essentially an indirect measure of the Endpoint's internal buffering. |
5 | 0h | RO | Extended Tag Field Supported (ETFG) This bit indicates the maximum supported size of the Tag field as a Requester.Defined encodings are: |
4:3 | 0h | RO | Phantom Functions Supported (PFS) 00b No Function Number bits are used for Phantom Functions |
2:0 | 2h | RW/O | Max_Payload_Size Supported (MPSS) This field indicates the maximum payload size that the Function can support for TLPs. Defined encodings are: |