Register Description

4.8.19ESMRAMC – Extended System Management RAM Control (Device #0)

Address Offset:

61h

Default Value:

38h

Access:

Read/Write/Lock

Size:

8 bits

The Extended SMRAM register controls the configuration of Extended SMRAM Space. The Extended SMRAM (E_SMRAM) Memory provides a Write-Back cacheable SMRAM Memory Space that is above 1 MB.

Bit

Description

 

 

7

H_SMRAM_EN (H_SMRAME): Controls the SMM Memory Space location (that is, above 1 MB

 

or below 1 MB). When G_SMRAME is 1 and H_SMRAME this bit is set to 1, the high SMRAM

 

Memory Space is enabled. SMRAM accesses from 0FEDA0000h to 0FEDBFFFFh are

 

remapped to DDR SDRAM address 000A0000h to 000BFFFFh.

 

Once D_LCK is set, this bit becomes Read Only.

 

 

6

E_SMRAM_ERR (E_SMERR): This bit is set when CPU accesses the defined DDR SDRAM

 

ranges in Extended SMRAM (High system memory and T-segment) while not in SMM Space. It

 

is software’s responsibility to clear this bit. The software must Write a 1 to this bit to clear it.

 

 

5

SMRAM_Cache (SM_CACHE): GMCH forces this bit to 1.

 

 

4

SMRAM_L1_EN (SM_L1): GMCH forces this bit to 1.

 

 

3

SMRAM_L2_EN (SM_L2): GMCH forces this bit to 1.

 

 

2:1

Reserved

 

 

0

TSEG_EN (T_EN): Enabling of SMRAM Memory (TSEG, 1 Mbytes of additional SMRAM

 

Memory) for Extended SMRAM Space only. When G_SMRAME =1 and TSEG_EN = 1, the

 

TSEG is enabled to appear in the appropriate physical address space.

 

Once D_LCK is set, this bit becomes Read Only.

 

 

D15343-003

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Intel D15343-003 manual Esmramc Extended System Management RAM Control Device #0