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TS-5700 User's Manual
4. Memory
4.1 SDRAM
The TS-5700 has a total of 32 Megabytes (MB) of high-speed SDRAM providing 640 Kilobytes (KB) of base
memory, 31 MB of extended memory, and 128 KB of shadow RAM for the BIOS. This is identical to a standard
PC memory map. The TS-5700 can be ordered with 64MB of SDRAM, but it is not field upgradeable.
The TS-5700 SDRAM chips are soldered directly to the board. By not using a SIMM socket, the TS-5700 is
much more reliable in high-vibration environments.
4.2 Flash
There is a total of 2 MB of Flash memory on the TS-5700 with 128 KB reserved for the BIOS. During POST, this
128 KB area is copied from Flash into SDRAM at addresses E0000h through FFFFFh for improved performance
(a standard technique known as BIOS Shadowing). The remainder of the Flash memory (1920 KB) is configured
as a solid-state disk (SSD) drive appearing as drive A. Drive A is fully supported by the BIOS as an INT 13h
drive.
The physical Flash memory is accessed by the BIOS in protected mode at memory address 148M.
The Flash memory is guaranteed capable of a minimum of 100,000 write/erase cycles. This means that if you
completely erase and rewrite the SSD drive 10 times a day you have over 27 years before any problems would
occur. Reading the SSD produces no wear at all.
Power failure during Flash writes can cause corruption of Flash drive FAT tables (A: or B:). Therefore
applications writing frequently should use a Compact Flash card drive which is much more tolerant of power
failures during write cycles.
Flash drive A is read-only when JP3 is not installed. Removing JP3 also makes the 128 kbyte BIOS area of the
Flash write protected as well. Write protecting the A: drive can be useful if there are critical files in the final
product that must be very secure.
4.3 Compact Flash Cards
If 2MB of Flash is insufficient for your application, additional non-volatile storage can be added with a Compact
Flash (CF) card. CF cards can supply additional storage that will behave much as a hard drive does in a typical
PC with sizes ranging from 8MB to 512MB. These products are inherently more rugged than a hard drive since
they are completely solid-state with no moving parts.
The Compact Flash card has the added advantage of being removable media. A SanDisk USB Compact Flash
reader/writer (which is included in the TS-5700 Developer's Kit) is recommended for the host PC for file
transfers. This results in the ability to quickly move files from a host PC to the TS-5700 using a Compact Flash
card as the removable media. Since the Compact Flash card appears as a standard IDE drive on the TS-5700, it
uses no additional RAM for drivers. While a USB Compact Flash reader allows for hot swapping of the Compact
Flash card on the host PC, the Compact Flash interface on the TS-5700 is not hot swappable, the TS-5700 must
be rebooted after removing or installing a Compact Flash card.
Technologic Systems
5
http://embeddedARM.com/
5/2009
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