Advantech ARK-3384 Series, Руководство пользователя

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37 Chapter 4
Figure 4.4: Advanced Chipset features screen
4.5.1 DRAM Timing Selectable
This option refers to the method by which the DRAM timing is selected.
The default is By SPD.
4.5.2 CAS Latency Time
You can configure CAS latency time in HCLKs as 2 or 2.5 or 3. The sys-
tem board designer should set the values in this field, depending on the
DRAM installed. Do not change the values in this field unless you change
specifications of the installed DRAM or the installed CPU.
4.5.3 Active to Precharge Delay
The default setting for the Active to Precharge Delay is 7.
4.5.4 DRAM RAS# to CAS# Delay
This option allows you to insert a delay between the RAS (Row Address
Strobe) and CAS (Column Address Strobe) signals. This delay occurs
when the SDRAM is written to, read from or refreshed. Reducing the
delay improves the performance of the SDRAM.
4.5.5 DRAM RAS# Precharge
This option sets the number of cycles required for the RAS to accumulate
its charge before the SDRAM refreshes. The default setting for the Active
to Precharge Delay is 3.