Figure 3.5: Advanced chipset features screen (b)

Note: DRAM default timings have been carefully cho- sen and should ONLY be changed if data is being lost. Please first contact technical sup- port.

3.5.1 DRAM Timing Selectable

This item allows you to control the DRAM speed. The selections are “Manual” or “By SPD”.

3.5.2 CAS Latency Time

When DRAM Timing Selectable is set to [Manual], this field is adjust- able. This controls the CAS latency, which determines the time interval between SDRAM starting a read command and receiving it. The options are [3T], [4T], [5T], and [Auto].

3.5.3 DRAM RAS# to CAS# Delay

When DRAM Timing selectable is set to [Manual], this field is adjust- able. When DRAM is refreshed, the rows and columns are addressed sep- arately. This setup item allows user to determine the timing of the transition from RAS (row address strobe) to CAS (column address strobe). The less the clock cycles are, the faster the DRAM speed is. Set- ting options are [2T] to [5T], and [Auto].

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Advantech DVMB-554E user manual Dram Timing Selectable, CAS Latency Time, Dram RAS# to CAS# Delay