Mc_Crdt_Wr_Thld; Mc_Scrubaddr_Lo - Intel I7-900 DESKTOP PROCESSOR - DATASHEET VOLUME 2 Datasheet

Register Description
2.8.9

MC_CRDT_WR_THLD

This is the Memory Controller Write Credit Thresholds register. 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.
Register programming rules:
• CRIT threshold value must correspond to the number of critical RTIDs reserved at
the IOH.
• HIGH threshold value must correspond to the sum of critical and high RTIDs
reserved at the IOH (which must not exceed 30).
• Set MC_Channel_*_WAQ_PARAMS.ISOCENTRYTHRESHHOLD equal to (31-CRIT).
Device:
Function: 0
Offset:
Access as a Dword
Bit
12:8
4:0
2.8.10

MC_SCRUBADDR_LO

This register contains part of the address of the last patrol scrub request issued. When
running Memtest, the failing address is logged in this register on Memtest errors.
Software can write the next address to be scrubbed into this register. Patrol scrubs
must be disabled to reliably write this register.
Device:
Function: 0
Offset:
Access as a Dword
Bit
29:14
13:0
Datasheet
3
74h
Reset
Type
Value
RW 4 HIGH. High Credit Threshold.
RW 3 CRIT. Critical Credit Threshold.
3
78h
Reset
Type
Value
RW 0 PAGE.
This field contains the row of the last scrub issued. Can be written to specify the
next scrub address with STARTSCRUB in the MC_SCRUB_CONTROL register.
RW 0 COLUMN.
This field contains the column of the last scrub issued. Can be written to specify
the next scrub address with STARTSCRUB in the MC_SCRUB_CONTROL register.
Description
Description
55