Instruction manual

3-13
BIOS Setup
Read Preamble value
When the User Config mode is set to [Manual], the field is adjustable. It
specifies the time prior to the max-read DQS-return when the DQS receiver
should be turned on. This is specified in units of 0.5ns. The controller needs to
know when to enbale its DQS receiver in anticipation of the DRAM DQS driver
truning on for a read. The controller will disable its DQS receiver until the read
preamble time and then enable its DQS receiver while the DRAM asserts DQS.
Setting options: [2ns] ~ [9.5ns].
Async Latency value
When the User Config mode is set to [Manual], the field is adjustable. This field
should be loaded with 4-bit value equal to the maximum asynchronous latency
in the DRAM read round-trip loop. Setting options: [2ns] ~ [11ns].
MTRR Mapping Mode
This setting controls the MTRR mapping mode. To install the WinXP64, this
setting should be set to [Continuous]. Setting options: [Continuous], [Discrete].