Apollo ESP6000 User Manual

Page of 104
ECM-3612 
 
66 ECM-3612 User’s Manual 
 
 
3.5.3 
Advanced Chipset Features 
This section allows you to configure the system based on the specific features of the 
installed chipset. This chipset manages bus speeds and access to system memory 
resources, such as DRAM and the external cache. It also coordinates communications 
between the conventional ISA bus and the PCI bus. It must be stated that these items 
should never need to be altered. The default settings have been chosen because they 
provide the best operating conditions for your system. The only time you might consider 
making any changes would be if you discovered that data was being lost while using your 
system. 
The first chipset settings deal with CPU access to dynamic random access memory 
(DRAM). The default timings have been carefully chosen and should only be altered if data 
is being lost. Such a scenario might well occur if your system had mixed speed DRAM 
chips installed so that greater delays may be required to preserve the integrity of the data 
held in the slower memory chips. 
 
3.5.3.1 DRAM 
Clock 
Set the memory bus frequency to operate at various values for the proper memory clock 
setting. 
The choices: Host CLK, HCLK-33M, HCLK+33M. 
3.5.3.2  SDRAM Cycle Length 
When synchronous DRAM is installed, the number of clock cycles of CAS latency depends 
on the DRAM timing. Do not reset this field from the default value specified by the system 
designer.
 
The choices: 3, 2.