Intel KM4AM - Manual (Page 44)

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BIOS Setup
DRAM CAS Latency
When synchronous DRAM is installed, the number of clock cycles of CAS latency
depends on the DRAM timing. The settings are: 1.5, 2, 2.5, 3.
Bank Interleave
This field selects 2-bank or 4-bank interleave for the installed SDRAM. Disable the
function if 16MB SDRAM is installed. Settings: Disabled, 2 Bank and 4 Bank.
Precharge To Active (Trp)
This item controls the number of cycles for Row Address Strobe (RAS) to be allowed
to precharge. If insufficient time is allowed for the RAS to accumulate its charge
before DRAM refresh, refreshing may be incomplete and DRAM may fail to retain
data. This item applies only when synchronous DRAM is installed in the system.
Available settings: 2T, 3T.
Trans Non-DDR400/DDR400
This controls the timing delay (in clock cycles) before non-DDR400 and DDR400
starts a write command after receiving it. Settings: 6T/8T, 7T/10T, 5T/6T, 8T/12T.
12T increases the delay time while 5T provides the least timing delay. This option is
effective only if DDR400 is running.
Active to CMD (Trcd)
When DRAM is refreshed, both rows and columns are addressed separately. This
setup item allows you to determine the timing of the transition from RAS (row address
strobe) to CAS (column address strobe). The less the clock cycles, the faster the
DRAM performance. Setting options: 2T, 3T.
DRAM Burst Length
This setting allows you to set the size of Burst-Length for DRAM. Bursting feature is
a technique that DRAM itself predicts the address of the next memory location to be
accessed after the first address is accessed. To use the feature, you need to define
the burst length, which is the actual length of burst plus the starting address and
allows internal address counter to properly generate the next memory location. The
bigger the size, the faster the DRAM performance. Settings: 4, 8.
DRAM Command Rate
This setting controls the SDRAM command rate. Selecting 1T allows SDRAM signal
controller to run at 1T (T=clock cycles) rate. Selecting 2T makes SDRAM signal
controller run at 2T rate. 1T is faster than 2T. Setting options: 1T Command, 2T
Command.
DDR Voltage
Adjusting the DDR voltage can increase the DDR speed. Any changes made to this
setting may cause a stability issue, so changing the DDR voltage for long-term
purpose is NOT recommended
.