Intel i7-2600 CM8062300834302S User Manual

76

Datasheet, Volume 2

This 64-bit register defines the Top of Upper Usable DRAM. 

Configuration software must set this value to TOM minus all Intel ME stolen memory if 
reclaim is disabled. If reclaim is enabled, this value must be set to reclaim limit + 
1 byte,  1 MB  aligned,  since  reclaim limit is 1 MB aligned. Address bits 19:0 are 
assumed to be 000_0000h for the purposes of address comparison. The Host interface 
positively decodes an address towards DRAM if the incoming address is less than the 
value programmed in this register and greater than or equal to 4 GB.

BIOS Restriction: Minimum value for TOUUD is 4 GB.

These bits are Intel TXT lockable.

63:39

RO

0h

38:20

RW-L

00000h

Uncore

TOUUD (TOUUD)
This register contains bits 38:20 of an address one byte above the 

maximum DRAM memory above 4 GB that is usable by the 

operating system. Configuration software must set this value to 

TOM minus all Intel ME stolen memory if reclaim is disabled. If 

reclaim is enabled, this value must be set to reclaim limit 1 MB 

aligned since reclaim limit + 1 byte is 1 MB aligned. Address bits 

19:0 are assumed to be 000_0000h for the purposes of address 

comparison. The Host interface positively decodes an address 

towards DRAM if the incoming address is less than the value 

programmed in this register and greater than 4 GB.
All the bits in this register are locked in Intel TXT mode.

19:1

RO

0h

0

RW-KL

0b

Uncore

Lock (LOCK)
This bit will lock all writeable settings in this register, including 

itself.