40
Embedded Modules
© Tibbo Technology Inc.
4.2.2.4
Serial Ports
The EM1000 has four serial ports that can work in one of the three modes: UART,
Wiegand, or clock/data. All three modes are described in detail in the documentation
for the serial (ser.) object found inside the TIDE, TiOS, Tibbo BASIC, and Tibbo C
Manual. Additionally, see the Platform-dependent Programming Information section
inside the EM1000 platform documentation (same manual).
4.2.2.5
Square Wave Generator
The square wave generator can produce a square wave output on pin GPIO45/CO of
the EM1000. This output is primarily intended for generating audio signals using
buzzer and is covered in the beep (beep.) object -- see the TIDE, TiOS, Tibbo
BASIC, and Tibbo C Manual.
4.2.2.6
Flash and EEPROM Memory
The EM1000 has 512KBytes or 1024KBytes of flash memory and 2KBytes of EEPROM
memory (see
Specifications and Ordering Info
).
The first 64KBytes of flash memory are used to store the TiOS firmware. When you
are performing a firmware upgrade it is this memory you are saving the firmware
binary into.
The rest of this flash memory is available to your Tibbo BASIC/C application and its
data. Whatever memory space is left after the compiled application is loaded can be
used as a flash disk (see fd. object documentation in the TIDE, TiOS, Tibbo BASIC,
and Tibbo C Manual).
The EEPROM is almost fully available to your application, save for a small 28-byte
area called "special configuration area". The EEPROM is accessed through the stor.
object (see TIDE, TiOS, Tibbo BASIC, and Tibbo C Manual). Details on the special
configuration area are provided in the Platform-dependent Programming Information
section inside the EM1000 platform documentation (same manual).
On the advice of one of our customers we are giving you the following
reminder: Like all other EEPROMs on the market, EEPROM ICs used in Tibbo
devices allow for a limited number of write cycles. As the Wikipedia article on
EEPROMs (
https://en.wikipedia.org/wiki/EEPROM
) states, the EEPROM "
...has a
limited life for erasing and reprogramming, now reaching a million operations in
modern EEPROMs. In an EEPROM that is frequently reprogrammed while the
computer is in use, the life of the EEPROM is an important design consideration.
"
When planning to use the stor. object, please carefully consider if the planned mode
of EEPROM use will allow the EEPROM to work reliably through the entire projected
life of your product. For more information see
Prolonging and Estimating EEPROM
Like all other flash memory devices on the market, flash ICs used in Tibbo products
only allow for a limited number of write cycles. As the Wikipedia article on flash
memory (
https://en.wikipedia.org/wiki/Flash_memory
) explains, modern flash ICs still
suffer from comparatively low write endurance. In Tibbo devices, this endurance is
around 100'000 write cycles per sector. When you are using the flash memory for
file storage, the fd. object employs sector wear leveling to maximize the life of the
flash IC (but the life still remains limited). If your application employs direct sector
access, then it is your job to plan the application around the life limitations of the
flash memory. For data that changes often, consider using the EEPROM memory
instead. EEPROMs have much better endurance.