50g interlaken ip core transmit path, 50g interlaken ip core transmit path -8 – Altera 50G Interlaken MegaCore Function User Manual
Page 34
In Packet mode, the 50G Interlaken IP Core performs Optional Scheduling Enhancement based on
Section 5.3.2.1.1 of the Interlaken Protocol Specification, Revision 1.2. The IP core ignores the
itx_sob
and
itx_eob
signals. Instead, the IP core performs optional enhanced scheduling based on the settings of
BurstMax
,
BurstMin
, and
BurstShort
.
In Interleaved mode, the 50G Interlaken IP Core inserts burst control words on the Interlaken link based
on the
itx_sob
and
itx_eob
inputs. The internal optional enhanced scheduling is disabled and the
BurstMax and BurstMin values are ignored. BurstShort is still in effect. To avoid overflowing the transmit
FIFO, you should not send a burst that is longer than 1024 bytes.
In Interleaved mode or in Packet mode, the 50G Interlaken IP core is capable of accepting non-
interleaved data on the TX user data transfer interface (
itx_din_words
). However, if the IP core is in
Interleaved mode, the application must drive the
itx_sob
and
itx_eob
inputs correctly.
In Interleaved mode or in Packet mode, the 50G Interlaken IP core can generate interleaved data transfers
on the RX user data transfer interface (
irx_dout_words
). The application must be able to accept
interleaved data transfers if the Interlaken link partner transmits them on the Interlaken link. In this case,
the Interlaken link partner must send traffic in Interleaved mode that conforms with the 50G Interlaken
IP core
BurstShort
value.
Note: Altera recommends that the transmitter (link partner) only send packets with a minimum packet
size of 64 bytes.
Related Information
•
on page 3-2
•
50G Interlaken IP Core User Data Transfer Interface Signals
on page 5-4
•
50G Interlaken IP Core Transmit Path
The 50G Interlaken MegaCore function accepts application data from up to 256 channels and combines it
into a single data stream in which data is labeled with its source channel. The 50G Interlaken TX MAC
and PCS blocks format the data into protocol-compliant bursts and insert Idle words where required.
50G Interlaken IP Core Transmit User Data Interface Examples
The following examples illustrate how to use the Altera 50G Interlaken IP core TX user data interface:
50G Interlaken IP Core Interleaved Mode (Segmented Mode) Example
50G Interlaken IP Core Packet Mode Operation Example
on page 4-10
50G Interlaken IP Core Back-Pressured Packet Transfer Example
on page 4-11
50G Interlaken IP Core Interleaved Mode (Segmented Mode) Example
In Interleaved Mode, you are responsible for scheduling the burst. You need to drive an extra pair of
signals, Start of Burst (SOB) and End of Burst (EOB), to indicate the burst boundary. You can send the
traffic in packet order or interleaved order, as long as you set the SOB and EOB flags correctly to establish
the data boundaries.
4-8
50G Interlaken IP Core Transmit Path
UG-01140
2015.05.04
Altera Corporation
Functional Description