Altera Corporation
2–185
October 2007
Stratix II GX Device Handbook, Volume 2
Stratix II GX Transceiver Architecture Overview
Figure 2–134. /I2/ Deleted When FIFO Count is Greater Than Nine
Figure 2–135. /I2/ Added When FIFO Count is Less Than Five
Reset Condition
After power up or reset, the GIGE transmitter outputs three /K28.5/
commas before user data can be sent. This affects the synchronization
ordered set transmission.
After reset (
tx_digitalreset
), the 8B/10B encoder automatically
sends three /K28.5/ commas (refer to
“8B/10B Decoder” on page 2–103
for additional information). Depending on when you start outputting the
synchronization sequence, there could be an even or odd number of
/Dx.y/ sent as the transmitter before the synchronization sequence. The
last of the three automatically sent /K28.5/and the first user-sent /Dx.y/
are treated as one idle ordered set. This can be a problem if there are an
even number of /Dx.y/ transmitted before the start of the
synchronization sequence.
Figure 2–136
shows an example of even numbers of /Dx.y/ between the
last automatically sent /K28.5/ and the first user-sent /K28.5/. The first
user-sent ordered set is ignored, so three additional ordered sets are
required for proper synchronization.
Figure 2–136
shows one don’t care
data between the
tx_digitalreset
signal going low and the first of
three automatic K28.5, but there could be more.
/D/
/D/
/D/
/D/
/D/
/S/
/|2/
/|2/
/|1/
To Rate Matcher
/D/
/D/
/D/
/D/
/D/
/D/
/S/
/|2/
/|1/
One /|2/ Code Removed
From Rate Matcher
/D/
/D/
/D/
/D/
/D/
/S/
/|2/
/|2/
/|1/
To Rate Matcher
/D/
/D/
/D/
/D/
/D/
/D/
/S/
/|2/
/|2/
/|2/
/|1/
One /|2/ Code Added
From Rate Matcher
Содержание Stratix II GX
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