2–182
Altera Corporation
Stratix II GX Device Handbook, Volume 2
October 2007
Native Modes
GIGE Transmitter Synchronization
The transmitter must send out the GIGE synchronization sequence to
synchronize the target receiver. Stratix II GX devices do not contain a
built-in macro that provides this function upon power-up or reset. You
must implement this function in user logic to send out a /K28.5/, /Dx.y/,
/K28.5/, /Dx.y/, /K28.5/, /Dx.y/ sequence.
Figure 2–130
shows an example of the GIGE synchronization pattern.
Although the example shows one D0.0 (8'h00) as the /Dx.y/ code, any
/Dx.y/ and any odd number of /Dx.y/ can be used.
Figure 2–130. GIGE Synchronization Transmit Pattern
GIGE Receiver Synchronization
You must pre configure the receiver with a K28.5 (10'b0101111100 or
10'b1010000011) word align pattern (
ALIGN_PATTERN
= 0101111100 or
ALIGN_PATTERN
= 1010000011). The
ALIGN_PATTERN_LENGTH
must be
set to 10 even though a 7-bit comma string (7'b0011111 as a comma- or
7'b1100000 as a comma+) is allowed as specified in IEEE 802.3. This 7-bit
comma is located within the /K28.1/, /K28.5/, and /K28.7/ code groups.
Using a 10-bit /K28.5/ helps prevent a 7-bit comma from being detected
across boundaries when a /K28.7/ code is followed by a /K28.x/,
/D3.x/, /D3.x/, /D11.x/, /D12.x/, /D19.x/, /D20.x/, or /D28.x/,
where
x
is a value from 0 to 7 (
Figure 2–131
).
Figure 2–131. Cross Boundary 7-bit Comma When a /K28.7/ is Followed by a /K28.5/ Code Group
GIGE Synchronization Pattern
GIGE Synchronization Pattern
00
BC
00
BC
00
BC
00
8D
tx_dataout[7..0 ]
clock
tx_ctrlenable
A4
0
1
0
1
1
1
1
1
0
0
0
0
0
1
1
1
1
1
0
0
K28.7
K28.5
7-bit comma-
7-bit comma+
7-bit comma-