ÉlanSC310 Microcontroller Evaluation Board User’s Manual
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DRAM Main Memory
The ÉlanSC310 microcontroller evaluation board comes standard with 2 Mbyte of
standard 30-pin, 70-ns DRAM SIMMs installed on the board. The evaluation board
requires DRAMs with access times of 70 ns or less (for 33 MHz operation). The
DRAM memory can be upgraded using 30-pin SIMMs with 4- or 8-bit DRAMs;
SIMMs with 1-bit DRAMs cannot be used on the evaluation board due to loading
restrictions associated with 32 loads.
16 Mbyte of main DRAM memory can also be installed using a 72-pin, 16-bit
SIMM module. This can be installed in the 72-pin SIMM socket located next to
main memory bank 1 on the evaluation board (see Figure 2-1 on page 2-2). 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.
BIOS automatically detects the amount of DRAM installed.
Memory Voltage Setting
The ÉlanSC310 microcontroller evaluation board allows system memory to
operate at either 5 V or 3.3 V. When operating in Local Bus mode, 3.3 V memory
must be used. In order to operate memory at 3.3 V, ensure that the memory is rated
for 3.3-V operation. SW4-1 controls the voltage for the system memory.
Total Memory
Bank 0
Bank 1
1 Mbyte
Two 512-Kbyte
Empty
2 Mbyte
Two 512-Kbyte
Two 512-Kbyte
2 Mbyte
Two 1-Mbyte
Empty
4 Mbyte
Two 1-Mbyte
Two 1-Mbyte
8 Mbyte
Two 4-Mbyte
Empty
16 Mbyte
Two 4-Mbyte
Two 4-Mbyte
SW4-1 Setting
Memory V
CC
OFF
3.3 V
ON
5 V
evalbd.book : ch2 Page 19 Thursday, August 8, 1996 2:34 PM