Octek Hippo-SX, Manual

Page: 26 / 68

CONFIGURING THE SYSTEM
__________________________________
CONFIGURATION OF MEMORY
The configuration of the memory is very flexible.
There are several combinations of DRAM types you may
consider. Either 256KB or 1MB SIMM are acceptable.
There are totally four banks of DRAM. Two banks
(bank 0 and 1) are on the motherboard and the others
(bank 2 and 3) are on the memory expansion board. If
bank 0 and 1 are filled, you have to use bank 2 and 3. If
you use 4MB module, bank 2 and bank 3 are not used.
Page mode is always active. Interleaved mode is
only enabled for those banks with similar pairs or quartet
of DRAMs. The memory size is detected automatically by
system BIOS and indicated during memory test after
reset. No jumper is needed to be set for the memory
size and DRAM type.
To determine what DRAM speed rating should be
used depends on the system speed and wait state. The
highest performance is accomplished by using zero wait
state, but high speed DRAM has to be used. If zero wait
state is selected, fast page mode DRAM is needed.
Select zero wait state for 100ns DRAM or faster.
120ns DRAM can be used for 1 wait state. The wait state
setting is applied to four banks of memory. Therefore
make sure to install DRAM with the same speed rating, or
accom-modate the wait state setting to the new DRAM
type.