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IEI Integration IMBA-9454 v1.00 User Manual

Page 169

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IMBA-9454 Motherboard

Page 151

the manufacturer's code. The SPD enables 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 can be manually set using

the DRAM sub-items

Enabled D

EFAULT

DRAM timing parameter are set according to the

DRAM Serial Presence Detect (SPD)

The Configure DRAM Timing by SPD option is disabled, the following configuration

options appear.

DRAM CAS# Latency [5]

DRAM RAS# to CAS# Delay [6 DRAM clocks]

DRAM RAS# Precharge [6 DRAM clocks]

DRAM RAS# Active to Precha [15 DRAM clocks]

DRAM CAS# Latency [5]

The DRAM CAS# Latency option refers to the Column Address Strobe (CAS) delay time.

To be able to change this configuration option the Configure DRAM Timing by SPD

configuration option must be set to “Disabled.” The following configuration options are

available.

3 nanoseconds

4 nanoseconds

5 nanoseconds

D

EFAULT

6 nanoseconds

DRAM RAS# to CAS# Delay [6 DRAM Clocks]

Use the DRAM RAS# to CAS# Delay option to specify the number of clock cycles must

elapse between sending a RAS (row address strobe) signal and the CAS (column address

strobe) signal. A pause is required between the RAS signal and the CAS signal to ensure

the memory is correctly addressed. To be able to change this configuration option the