Hi,
check design guide 3.4.3 GCKE and DCLKRD/DCLKWR Connection
download.intel.com/design/chipsets/designex/29063401.pdf
Module Mode Configuration (MMCONFIG). This bit is set by an external strapping option. The combination of this bit and the SDRAMPWR bit (SDRAMC register) determine the functioning of the CKE signals as defined as follows: SDRAMPWR MMCONFIG CKE Operation 0 0 3 DIMM, CKE[5:0] driven, self-refresh entry staggered. 5 SDRAM dynamic power down available. X 1 3 DIMM, CKE0 only, self-refresh entry not staggered. SDRAM dynamic power down unavailable. 1 0 4 DIMM, GCKE only, self-refresh entry staggered. SDRAM dynamic power down unavailable. NOTE: Under MMCONFIG mode, the AGP must be disabled.
download.intel.com/design/chipsets/datashts/29063301.pdf
If you just know this, please disregard this mail
Rudolf