Introducing the BIOS

3-15

 

 

Advanced DRAM Control 1:

This item can let you set several items concerning the DRAM parameters. If you do not understand what each item does, please keep the default settings. Wrong settings may cause system unstablity, data loss or even prevent boot up!

Figure 3-5B. Advanced DRAM Control 1 Screen Shot

System Performance:

Six options are available: Manual Mode ) Safe Mode ) Normal Mode ) Fast Mode ) Turbo Mode

)Ultra Mode. The default setting is Normal Mode. If you choose the Manual Mode, the following items will be available.

"DDR RAS Precharge Time (tRP):

Three options are available: 3T ) 2T ) 4T. The default setting is 3T. This item is to set SDR/DDR SDRAM RAS precharge time. It can define the SDRAM precharge to ACT command period.

tRP timing value (Precharge time – time from precharge command to when back can be activated).

"DDR RAS to CAS Delay (tRCD):

Three options are available: 3T ) 2T ) 4T. The default setting is 3T. This item is to set SDR/DDR SDRAM RAS to CAS delay. It can define the SDRAM ACT to Read/Write command period.

tRCD timing value = RAS to CAS latency + rd/wr command delay

"DDR Write Recovery Time (tWR):

Two options are available: 2T ) 1T. The default setting is 2T. This item is to set SDR/DDR SDRAM write recovery time. This item (bit) controls the number of clock cycles that must occur from the last valid write operation to the earlist time a new Precharge command can be asserted to the same bank. When you set it to 1T, tWR duration is 1 clock cycle, etc.

User’s Manual