Advantech DVMB-554E User Manual

Page of 94
 
 
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].