ÉlanSC310 Microcontroller Evaluation Board User’s Manual
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Evaluation Board Restrictions
• The evaluation board ISA bus can only run at 5 V. In normal designs this is not
a restriction.
• The DRAM SIMM modules must have a 70-ns or less RAS access time, for 33
MHz operation.
• The DRAM on the SIMM modules must be x4, x8 or x16. The ÉlanSC310
microcontroller cannot drive x1 DRAM due to the large capacitance associated
with 32 loads.
• System DRAM population of both the 30-pin SIMM sockets and the 72-pin
SIMM socket is not supported simultaneously.
• On the 72-pin SIMM socket, only 16-bit SIMM modules are fully supported.
32-bit SIMMs can be used in the 72-pin SIMM socket but only half of the
memory will be visible.
• Software cannot be used to switch between ISA and local bus configurations.
One of the configurations must be set up before power-up.
• The BIOS ROM sockets (U20 and U59) can only be populated with the
following (the AMD recommended part is also listed):
– 128Kx8 ROM/EPROM (AMD 27C010)
– 256Kx8 ROM/EPROM (AMD 27C020)
– 128Kx8 Flash (AMD 12-V 28F010 or 5-V 29F010)
– 256Kx8 Flash (AMD 12-V 28F020 or 28F020A)
evalbd.book : ch2 Page 4 Thursday, August 8, 1996 2:34 PM