Datasheet

Processor Integrated I/O (IIO) Configuration Registers
190 Datasheet, Volume 2
3.3.3.45 IRPEGCREDITS—R2PCIe Egress Credits Register
This register specifies the Credits used by IRP when transmitting messages to various
destinations on various rings. BIOS should leave this register at default unless noted
otherwise in the individual bit descriptions. These registers are made CSR only for the
scenario that this might be needed for testing purposes.
IRPEGCREDITS
Bus: 0 Device: 5 Function: 0 Offset: 840
Bit Attr
Reset
Value
Description
63:34 RV 0h Reserved
33:30 RW-L 8h
FIFO Credits
The IRP has a FIFO on the inbound path feeding the R2PCIe. This is only a staging
FIFO to assist in the flow of inbound traffic. This field specifies the number of FIFO
entries to use in this IRP staging FIFO.
29:28 RW-L 1h
IIO to UBox NCB/NCS Credits
This field specifies the number of credits allocated for IIO to UBox NCB and NCS
combined. Uses entries in R2PCIe BL Pool B.
27:24 RW-L 8h
IIO IDI Credits
Specifies the credits used for:
• I2U data for VC0
• I2U data VC1/VCm
•I2U data VCp
•DRS to CBox
These use R2PCIe BL Pool A entries.
23:22 RW-L 1h BL Egress - DRS to Intel QPI Credits
21:20 RW-L 1h
AD Egress - IIO VC1 Credits
This field specifies the credits used for VC1 and VCm combined. Uses R2PCIe AD
Pool A credits.
19:18 RW-L 1h AD Egress - IIO VCp Credits
17:14 RW-L 9h AD Egress - IIO VC0 Write Credits
13:10 RW-L Bh
AD Egress - IIO VC0 Read Credits
These are the total credits allocated for read requests for VC0. There are three
transaction types that can use this pool:
• Non-posted read requests (used for remote peer-to-peer)
A credit from this pool will be used to send these.
• Posted read requests (used for read requests to HA, either local or remote)
A credit from this pool will be used to send these.
A credit from the vc0_rd_p0_cdt_threshold pool will be used.
• NDR to Intel QPI requests
A credit from the qpi_ndr_cdt_threshold will be used.
If more than one credit is used, then a credit will be used from this pool too.
The total number of credits reserved for all three types is 12, regardless of how
these registers are programmed.
9:6 RW-L 7h
AD Egress – IIO VC0 Non-Posted Read Credits
This field represents how many of the vc0_rd_cdt_threshold credits may be used
for non-posted reads (remote peer-to-peer).
Posted read requests (used for read requests to HA, either local or remote)
A credit from this pool will be used to send these.
A credit from the vc0_rd_cdt_threshold pool will be used.
5:3 RW-L 7h IIO to CBox NDR Credits
2:0 RW-L 4h
AD Egress - IIO NDR to Intel QPI Credits
These are the total credits allocated for NDR packets.
NDR to Intel QPI requests
• If more than one credit is used, a credit from the vc0_rd_cdt_threshold pool
will be used.
• A credit from this pool will be used.
The first credit out of this pool is not shared with vc0_rd_cdt_threshold, but all
additional credits are shared from that pool.