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TLK2541 K characters' setting --- full speed & half speed
I have questions about TLK2541 using mode,
1) In the GigEther mode, when the higher order byte is in idle, which K character should be set? And when the lower order byte is in idle, which K character should be set?
2) When used in full speed rate mode, that means both the higher and lower byte are used as valid data byte, then what K character should be set?
Thanks very much for help ☺
Here is some feedback on the question:
The GigEther mode works with the two IDLE codes defined in the
Ethernet standard. These are K28.5,D16.2 and K28.5,D5.6.
The Ethernet standard specifies that K28.5,D5.6 should be sent as
the first idle in a burst of idles if the running disparity is + to flip the
running disparity to -. All remaining idles in the burst would be
K28.5,D16.2. If the running disparity was – at the beginning of the burst
only K28.5,D16.2 idles should be sent.
A user of the TLK2541 has no way of knowing what the current
running disparity is so we included the GigEther mode. In this mode, the
actual idles sent on the serial lines will always follow the rules described
above as long as the parallel data is either K28.5,D16.2 or K28.5,D5.6.
It really doesn’t matter which of these two D codes is sent since the TLK2541
will always choose the correct one based on current running disparity. I would
If the customer is using the GigEther mode in full rate they can
In half rate mode, the idle is still composed of two bytes that
need to be interleaved on the TXD bus. TXD[16,7:0] needs to alternate
between 9’b110111100 and 9’1101010000 with 9’b110111100 always being sent first
because the K28.5 must always be in the LSB position of a compliant data
From: Frank Xie
Sent: Monday, March 22, 2010 8:43 AM
Subject: [INT - High Speed Interface Forum] TLK2541 K characters'
setting --- full speed & half speed
1) In the GigEther mode, when the higher order byte is in idle, which K
character should be set? And when the lower order byte is in idle, which K
character should be set?
2) When used in full speed rate mode, that means both the higher and lower
byte are used as valid data byte, then what K character should be set?
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