EP4CE30F29C7N Datasheet, PDF (342/488 Pages) Altera Corporation – Cyclone IV Device Handbook, Volume 1

1–62
Chapter 1: Cyclone IV Transceivers Architecture
Transceiver Functional Modes
Figure 1–57 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
/K28.5/ code group received at an odd code group boundary in cycle n + 3 takes the
receiver synchronization state machine in Loss-of-Sync state. The first
synchronization ordered-set /K28.5/Dx.y/ in cycles n + 3 and n + 4 is discounted and
three additional ordered sets are required for successful synchronization.
Figure 1–57. Example of Reset Condition in GIGE Mode
n
n+1 n+2 n+3 n+4
clock
tx_digitalreset
tx_dataout K28.5 xxx K28.5 K28.5 K28.5 Dx.y Dx.y K28.5 Dx.y K28.5 Dx.y K28.5 Dx.y
Running Disparity Preservation with Idle Ordered Set
During idle ordered sets transmission in GIGE mode, the transmitter ensures a
negative running disparity at the end of an idle ordered set. Any /Dx.y/, except for
/D21.5/ (part of /C1/ ordered set) or /D2.2/ (part of /C2/ ordered set) following a
/K28.5/ is automatically replaced with either of the following:
■ A /D5.6/ (/I1/ ordered set) if the running disparity before /K28.5/ is positive
■ A /D16.2/ (/I2/ ordered set) if the running disparity before /K28.5/ is negative
Lane Synchronization
In GIGE mode, the word aligner is configured in automatic synchronization state
machine mode that complies with the IEEE P802.3ae standard. A synchronization
ordered set is a /K28.5/ code group followed by an odd number of valid /Dx.y/ code
groups. Table 1–19 lists the synchronization state machine parameters that
implements the GbE-compliant synchronization.
Table 1–19. Synchronization State Machine Parameters ⁽¹⁾
Parameter
Number of valid synchronization ordered sets received to achieve
synchronization
Number of erroneous code groups received to lose synchronization
Number of continuous good code groups received to reduce the error count by
one
Note to Table 1–19:
(1) The word aligner supports 7-bit and 10-bit pattern lengths in GIGE mode.
Value
3
4
4
Cyclone IV Device Handbook,
Volume 2
October 2013 Altera Corporation