
ÉlanSC310 Microcontroller Evaluation Board User’s Manual
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Address Mapping of the Flash/EPROM Sockets
The BIOS sockets have an 8-bit interface. Only one socket (U20) or (U59) can be
enabled depending on the setting of jumper JP32. Address lines A0–A17, 256K
addressing, are connected to the socket. The BIOS ROM can be accessed for
programming by either using an MMS page, or setting up a linear decode region
(see the ÉlanSC310 Microcontroller Programmer’s Reference Manual).
Typically, an MMS page is used.
The application sockets have a 16-bit interface. If BIOS does not already enable
the 16-bit interface, this needs to be done after boot-up by setting to a 1 bit 1 of
the ÉlanSC310 Index 51h. Even addresses access sockets U16 and U18. Odd
addresses access sockets U17 and U19. Support for both 256Kx8 Flash or EPROM,
and 512Kx8 EPROM parts exists. Jumper JP13 controls which is selected.
NOTE:
512Kx8 Flash can be supported after a minor board rework. Contact your
local AMD or distributor Field Application Engineer for more information.
When set for 256Kx8 parts: even addresses from 0–7FFFEh access socket U16;
odd addresses from 1–7FFFFh access socket U17; even addresses from 80000h–
FFFFEh access socket U18; and odd addresses from 80001h–FFFFFh access
socket U19.
When set for 512Kx8 parts: even addresses from 0–FFFFEh access socket U16;
odd addresses from 1–FFFFFh access socket U17; even addresses from 100000h–
1FFFFEh access socket U18; and odd addresses from 100001h–1FFFFFh access
socket U19. The application address space is accessed by using an MMS page or
by enabling the linear decode for the application ROM. Using an MMS page is
recommended because it can be accessed using real mode addressing.
Evaluation Board Jumper Settings
There are three jumpers which affect Flash programming on the ÉlanSC310
microcontroller evaluation board.
JP32:
This jumper controls whether BIOS socket U20 (JP32=2-3) or socket
U59 (JP32=1-2) is used.
JP12:
This jumper must be set to 1-2 when Flash parts are used (JP12=2-3
indicates EPROM parts).
evalbd.book : ch4 Page 6 Thursday, August 8, 1996 2:34 PM