HOT-555 User's Manual 12
Chapter
3
Memory Configuration
The HOT-555 mainboard provides four 72-pin SIMM sockets and two 168-
pin DIMM sockets that make it possible to install up to 128MB of RAM.
The SIMM socket support 4MB, 8MB, 16MB, and 32MB single- or double-
side fast page or EDO DRAM modules. Memory timing requires 70 ns fast
page devices or, for optimum performance, 60 ns EDO DRAM or 70 ns
Synchronous DRAM may be used. Both parity and non-parity memory are
supported.
The four SIMM sockets are arranged in two banks of two sockets each and
the two DIMM sockets are arranged in two banks of one socket each. Each
bank provides a 64/72-bit wide data path.
Both SIMMs in a bank must be of the same memory size and type, although
the different types of memory may differ between banks. It is possible to
have 70 ns fast page DRAM in one bank and 60 ns EDO DRAM in the other.
The DIMM socket share the same address lines with SIMM socket, there
have some restriction of memory configuration, please refer to Table 3-1,
Table 3-2, and Table 3-3.
Table 3-1. Restriction of Memory Configuration
SIMM 1, 2
( J2, J3 )
SIMM 3, 4
( J4, J5 )
DIMM 1
( DIM1 )
DIMM 2
( DIM 2)
Description
Single-bank
Single-bank
Single-bank
Single-bank
Single-bank SIMM include 4 MB and 16 MB.
Double-bank SIMM include 8 MB and 32 MB.
Single-bank DIMM include 8 MB and 32 MB
Double-bank DIMM include 16 MB.
Single-bank
Double-bank
Single-bank
Not Available
Double-bank
Single-bank
Not Available
Single-bank
Empty
Empty
Double-bank
Double-bank
Double-bank
Double-bank
Not Available
Not Available
Single-bank
Empty
Single-bank
Double-bank
Empty
Single-bank
Double-bank
Single-bank
