Octagon 6000 Series, User Manual

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9-1
6000 Series user’s manual SSDs, DRAM, and battery backup
Chapter 9:
SSDs, DRAM, and battery backup
Before you can save and boot your application from the PC Microcontrol-
ler, this chapter describes how to configure the system for your particu-
lar application requirements. The following topics are discussed:
„
SSD0
„
SSD2
„
DRAM
„
Real time clock
„
Battery backup for SSD2 and real time calendar/clock
≡
SSD0
SSD0 contains the BIOS and ROM-DOS 6.22 in flash ROM. It reserves
128 KB for BIOS and 896 KB for a drive area. SSD0 is a DOS-compat-
ible read/write drive.
Your application programs can be saved to flash using the PICO FA
driver which makes the flash memory a read/write disk on your PC
Microcontroller. Saving your application programs onto the read/write
disk allows you to update them at least 100,000 times. These devices
are erased automatically during the programming process.
SSD0 can be accessed directly as a read/write DOS drive with the PICO
FA driver in the BIOS extension. Also, it can be accessed directly as a
read/write DOS drive when the PICOFA.SYS driver is loaded. While
this is convenient for product development, the flash, however, has a
limited number of writes allowed. Therefore, Octagon does not recom-
mend SSD0 be used as a data logging device. Refer to the
Software
utilities chapter for information on supported flash memory and a
description of PICO FA.
≡
SSD2
SSD2 contains 128 KB of SRAM. SSD2 can be accessed directly as a
read/write DOS drive with the PICO FA BIOS extension. SSD2 is
generally used for data logging.
WARNING!
The on–board battery is not intended to back up SSD2. Use
an external AT style battery to back up SSD2. Failure to do
so may result in lost data.