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Embedded Modules
© Tibbo Technology Inc.
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.
4.4.1.4
LED Lines
The EM510 has three LED control lines -- SG, SR, SE. All lines have the same
internal structure and the LEDs should be connected as shown on the schematic
diagram below. The maximum load for each line is 10mA. For a small LED, a 330 Ohm
series resistor will provide sufficient brightness.
The SG and SR lines are used to control two status LEDs found on Tibbo products.
These LEDs can show various flashing patterns indicating the current device state
(see
). On the EM510, there is an added twist: the same pair of status
LEDs also indicates the current Ethernet link status through LED brightness. We
refer to the EM510's status LEDs as "dual-function LEDs." This is a patented
featured available exclusively on our MiniMo (R) devices. Here is how this works:
When a "live" Ethernet cable is not plugged into the RJ45 jack, flashing patterns
displayed by the status LEDs are "dimmed". That is, LEDs turn on at around 20% of
their nominal brightness. When a "live" Ethernet cable is plugged into the RJ45 jack,
flashing patterns are displayed at full brightness.
This dual functionality was designed into the EM510 for an important reason: Many
popular RJ45 jacks have two internal LEDs. With the EM510, it is possible to use
these LEDs both for the module state indication, and for Ethernet link indication.
This eliminates the need for any additional LEDs.
The third LED control line — SE — is a separate line for Ethernet link indication. The
SE LED will be on when the Ethernet interface is in the linked state.
There is no indication of the Ethernet link speed on the EM510.