Teknor Industrial Computers PCI-993, Техническое справочное руководство

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System 6-17
6.06 SYSTEM MEMORY (DRAM)
A local DRAM controller is integrated in the System Controller. Dynamic Random
Access Memory (DRAM) is essential system memory. The memory array is 64 bits
wide and ranges in size from 2MB to 128MB (256MB when available). The array is
implemented using single-sided or double-sided SIMMs (Single In-line Memory
Modules). See section 1 for instructions on configuring and installing SIMMs.
The location of the four 72-pin vertical SIMM sockets appears on Diagram 6-2 at U23,
U24, U25 and U26 (# 2).
The DRAM Controller supports CPU and PCI master accesses to System Memory. The
System Controller’s DRAM interface supplies the control signals and address lines; the
Data Controllers supply the data path from or to the CPU; and the PCI Controller’s
DRAM interface provides a 32-bit data link to the System Memory to allow for
concurrent CPU/Cache and PCI Master/DRAM operations.