User Manual

NANO-9452 EPIC Motherboard
Page 139


Auto DEFAULT
Automatically selects the DRAM frequency
 Configure DRAM Timing by SPD [Enabled]
Use the Configure DRAM Timing by SPD option to determine if the system uses the
SPD (Serial Presence Detect) EEPROM to configure the DRAM timing. The SPD
EEPROM contains all necessary DIMM specifications including the speed of the individual
components such a s CAS and ban k cycle time a s well as valid setti ngs for the module and
the manufacturer's code. The SPD enab les the BIOS to read the spec sheet of the DIMMs
on boot-up and then adjust the memory timing parameters accordingly.


Disabled
DRAM timing parameters are manually set using the
DRAM sub-items


Enabled DEFAULT
DRAM timing parameter are set according to the
DRAM Serial Presence Detect (SPD)
If the Configure DRAM Timing by SPD option is disabled, the following configuration
options appear.
 DRAM CAS# Latency [3]
 DRAM RAS# to CAS# Delay [5 DRAM Clocks]
 DRAM RAS# Precharge [5 DRAM Clocks]
 DRAM RAS# Activate to Precharge [15 DRAM Clocks]
 DRAM CAS# Latency [3]
Use the CAS Latency Time configuratio n option to set the Column Address Stro be (CAS)
delay time. (To be able to change this configuration option the DRAM Latency Timing
configuration option must be set to “Manual”) The following configuration options are
available
 5 nanoseconds
 4 nanoseconds
 3 nanoseconds D
EFAULT