Intel Xeon® Processor X3430 (8M Cache, 2.40 GHz) BX80605X3430 User Manual
Product codes
BX80605X3430
Intel® Xeon® Processor 3400 Series Datasheet, Volume 2
221
Processor Uncore Configuration Registers
4.7.10
MC_CRDT_WR_THLD
Memory Controller Write Credit Thresholds. A Write threshold is defined as the number
of credits reserved for this priority (or higher) request. It is required that High
threshold be greater than or equal to Crit threshold, and that both be lower than the
total Write Credit init value. BIOS must initialize this register with appropriate values
depending on the level of Isoch support in the platform. The new values take effect
immediately upon being written.
of credits reserved for this priority (or higher) request. It is required that High
threshold be greater than or equal to Crit threshold, and that both be lower than the
total Write Credit init value. BIOS must initialize this register with appropriate values
depending on the level of Isoch support in the platform. The new values take effect
immediately upon being written.
Register programming rules:
• CRIT threshold value must correspond to the number of critical RTIDs reserved at
the IIH.
• HIGH threshold value must correspond to the sum of critical and high RTIDs
reserved at the IIH (which must not exceed 30).
• Set MC_Channel_*_WAQ_PARAMS.ISOCENTRYTHRESHHOLD equal to (31-CRIT.)
Device:
3
Function: 0
Offset:
74h
Access as a DWord
Bit
Attr
Default
Description
31:13
RO
0
Reserved
12:8
RW
4
HIGH
High Credit Threshold.
High Credit Threshold.
7:5
RO
0
Reserved
4:0
RW
3
CRIT
Critical Credit Threshold.
Critical Credit Threshold.