Physical Memory - GE VMIVME-7805 Hardware Reference Manual

2.2 Physical Memory

26 VMIVME-7805/VME-7805RC Hardware Reference Manual
The VMIVME-7805/VME-7805RC provide DDR Synchronous DRAM (SDRAM)
as onboard system memory. Memory can be accessed as bytes, words or
longwords.
The VMIVME-7805/VME-7805RC accept one PC1600 DDR SDRAM SODIMM for
a maximum capacity of 1 GByte. The onboard SDRAM is dual-ported to the VME
through the PCI-to-VME bridge and is addressable by the local processor, as well
as the VME slave interface by another VME master. Caution must be used when
sharing memory between the local processor and the VME to prevent a VME
master from overwriting the local processor's operating system.
NOTE
When using the Configure utility of GE IOWorks Access to configure RAM, do not request more than
25 percent of the physical RAM. Exceeding the 25 percent limit may result in known bugs that
causes unpredictable behavior during the boot sequence and requires the use of an emergency
repair disk to restore the computer. It is recommended that an emergency repair disk be kept up-
to-date and easily accessible.
The VMIVME-7805/VME-7805RC include 32 KByte of nonvolatile SRAM which
can be accessed by the CPU at any time and is used to store system data that must
not be lost during power-off conditions.
NOTE
Memory capacity may be extended as parts become available.