Specifications

Hardware Configuration
2–29
2.11.6 Using Flash EPROMs
Flash programming power for +12V Flash devices is provided by an on-board power supply. You do
not need to connect an external +12V power supply to program Flash devices. Programming power is
switched under software control so that it is applied only during the actual programming process (to
prevent accidental corruption of the data). A utility for programming supported Flash devices is
included on the utility disk that is provided with the Little Board/486i Development Kit.
Some Flash EPROMs draw current through their chip select lines (or other pins) when powered down.
If you install a Flash EPROM in socket S0, make sure the jumper on W2 is removed and the jumper
on W21 is on 2/3 to prevent premature discharge of the on-board backup battery.
Flash EPROM
Typical Devices Pins Jumper Diagram
32K 5V Flash EPROM
29C256
28
32K 5V Flash EPROM 28C256 28
64K 5V Flash EPROM 29F512
128K 5V Flash EPROM 29F010
256K 5V Flash EPROM 29F020
512K 5V Flash EPROM 29F040
32
32K 12V Flash EPROM 28F256
64K 12V Flash EPROM 28F512
128K 12V Flash EPROM 28F010
256K 12V Flash EPROM 28F020
32
NOTE: W2 and W21 configure S0 only.
Figure 2-10 Flash EPROM Jumpering for S0 and S1
2.11.7 Using SRAMs
If you install an SRAM in socket S0, you can provide backup power from the battery when power is
off by shorting W2 and W21-1/2.
Battery backup is provided for S0 only (not S1).