Altera Interlaken MegaCore Function - Manual (Page 29)

Chapter 4: Functional Description 4–3
Interfaces Overview
June 2012 Altera Corporation Interlaken MegaCore Function
User Guide
The Interlaken MegaCore function value for the Interlaken BurstMax parameter is
configurable. You can specify BurstMax to be dynamically configurable or you can
configure a static value in the Interlaken parameter editor, as described in
Chapter 3,
Parameter Settings . The Interlaken MegaCore function supports two values for
BurstMax, 128 bytes and 256 bytes. The default static value is 128 bytes for all
variations.
The default value of BurstShort in Interlaken MegaCore function variations with a
512-bit wide datapath is 32 bytes. However, for these variations, you can specify
BurstShort to be dynamically configurable to 32 bytes or 64 bytes, or you can
configure a static value of 32 bytes or 64 bytes, as described in
Chapter 3, Parameter
Settings .
Table 4–1 shows the Interlaken MegaCore function values for the Interlaken
BurstShort parameter.
The Interlaken MegaCore function does not support BurstMin.
If you do not expose the in-band flow control calendar bits, the Interlaken MegaCore
function supports the following in-band flow control format for the RX and TX
calendar bits:
■ Bit 0: XON/XOFF bit for Channel 0
■ Bit 1: XON/XOFF bit for Channel 1
If you expose the calendar ports, the application determines the use of the in-band
flow control bits the MegaCore function receives on the incoming Interlaken link, and
the application is responsible for specifying the values of the in-band flow control bits
the MegaCore function transmits on the outgoing Interlaken link. In this case, you can
configure your MegaCore function to use 1, 8, or 16 pages of 16 calendar bits. For
more information, refer to
“Calendar and Status Block” on page 4–20 .
f The Interlaken Protocol Definition, Revision 1.2 is available from the Interlaken Alliance
website at
www.interlakenalliance.com .
Table 4–1. BurstShort Value in Bytes
Number of Lanes
Lane Rate (Gbps)
3.125 6.25 6.375 10.3125
4 16 (1) 16 (1) 16 (1) —
8 16 (1) 32 32 —
10 — 32 32 —
12 — 32 32 32 or 64
20 — 32 or 64 32 or 64 —
Note to Table 4–1 :
(1) The BurstShort value for Interlaken MegaCore function variations with a 128-bit wide datapath increases link
utilization while preventing multiple burst control words in the same clock cycle.