8-bit MicrocontrollersのトピックEEPROM necessary for 802.15.4?

EEPROM necessary for 802.15.4?

CometWay — Sat, 22 Sep 2007 02:01:27 GMT

Hello we are designing a board based on the MC1321xEVKRM (SRB) for use with 802.15.4 and/or BeeStack networking models. Something in my reading causes me to believe that the EEPROM is used during network to store transient routing tables and such, but I can no longer find out what I read on the topic.

Our board designers would of course like to remove the EEPROM from our design as we do not use it ourselves, but I have cautioned them based on my suspicion that this is used by the Beekit networking software.

Can anyone confirm this and/or point me to a relevant reference for further study?

I've seen that someone here is storing the PAN ID in flash. I assume this thread is related for the same reasons, but I'm still quite new at this whole Beekit thing.

Thank you for any advice you can offer! -pc

Re: EEPROM necessary for 802.15.4?

CometWay — Sat, 22 Sep 2007 03:09:28 GMT

OK I think I've found the references I was looking for regarding the
EEPROM or rather NVM (non-volitile memory) API.

According to this the EEPROM isn't used for the networking, but could
be if desired.

We don't need the EEPROM chip. -pc

Chapter 1 of the FSPRM.pdf mentions that the design of the NVM (non-
volitile memory) API supports its use with FLASH, static RAM, or EEPROM.

Chapter 8 of the FSPRM.pdf talks about it in more detail:

8.1 Non-Volatile Memory Overview
The NVM system uses some of the HCS08 flash memory for storage. Three
512 byte pages are
reserved for storage, 2 of which are in use at any given time with
one spare for writing new data.
NVM must be managed carefully. The data sheet for the HCS08 lists
Up to 100,000 program/erase cycles at typical voltage and temperature
Given a 20 year lifespan for a product, the flash memory should not
be written to more than once
every 1.8 hours on average.

...

In BeeStack, NvSaveOnIdle() is used just after the node joins the
network and has retrieved
the network security key. This way, if the node is reset it will
still be on the network.
NvSaveOnInterval() is used when new routes or neighbors are discovered.
NvSaveOnCount() is used in a secure network upon every message sent
or received to update
the security counters and store them only once every 256 messages.
This prevents a node from
saving too often and cause the flash to fail.

Re: EEPROM necessary for 802.15.4?

Jah123 — Tue, 06 Nov 2007 13:39:08 GMT

The EEPROM is used for the OTAP (over the air programming) and not normally required.