www.etherdecode.com |
|||
Etherdecode ethernet protocol decoder |
|||
Realtime 100Mbit ethernet triggering and decoding, for use with a mixed-signal oscilloscope or logic analyser. | |||
Home | FAQs | Contact and ordering info | Background & future developments |
Can't I do all this with Wireshark ?
To some extent (and more), but the point of Etherdecode is
that you can see ethernet timing relative to other signals. You may also prefer
a scope type user interface
Will it work with those really cheap 8-channel USB logic
analysers ?
Yes, but probably not very well. If you only use it to generate an
ethernet trigger then it may be quite useful, however as the decoding
functionality uses all 8 channels, it doesn't allow viewing of ethernet
packets relative to other signals so Wireshark may be a better solution.
Secondly, these cheap USB analysers typically sample at 24MHz, so the 12.5MHz
output rate of Etherdecode will make the bus data look rather uneven as the
sample rate is marginal. See this Screenshot
- you can see that every 11th or 12th sample is shorter
If I just want ethernet triggering, can't I just connect a scope
to the ethernet signals?
No, because of the complex encoding used by 100Mbit Ethernet, it is not
possible to distinguish between idle and when a packet is being sent by scoping the
signals on the cable. scope screenshot
Why not use SPI or UART instead of parallel bus?
The parallel data rate ia 12.5MHz, so a serial format would need
to output at 100MHz, and no scope can do decoding that fast.
What is the minimum useable spec for MSO/logic analyser ?
At least 8 digital channels ( 3.3v logic levels), minimum recommended
sampling frequency 25MHz. Ability to display 8 channels as a single bus.