HC4GX15 Datasheet, PDF (423/668 Pages) Altera Corporation – HardCopy IV Device Handbook

Chapter 1: HardCopy IV GX Transceiver Architecture
Functional Modes
1–159
After alignment of the first ||A|| column, if three additional aligned ||A||
columns are observed at the output of the deskew FIFOs of the four channels, the
rx_channelaligned signal is asserted high, indicating channel alignment is
acquired. After acquiring channel alignment, if four misaligned ||A|| columns are
seen at the output of the deskew FIFOs in all four channels with no aligned ||A||
columns in between, the rx_channelaligned signal is de-asserted low, indicating
loss-of-channel alignment.
The deskew FIFO operation in XAUI functional mode is compliant with the PCS
deskew state machine diagram specified in clause 48 of the IEEE P802.3ae, as shown
in Figure 1–127.
Figure 1–127. Deskew FIFO in XAUI Mode (Note 1)
SUDI(![/||A||/])
reset +
(sync_status=FAIL * SUDI)
LOSS_OF_ALIGNMENT
align_status ⇐ FAIL
enable_deskew ⇐TRUE
AUDI
sync_status OK * SUDI(![/||A||/])
deskew_error * SUDI
ALIGN_DETECT_1
enable_deskew ⇐ FALSE
AUDI
SUDI(![/||A||/])
!deskew_error
* SUDI(![/||A||/])
deskew_error * SUDI
ALIGN_DETECT_2
AUDI
SUDI(![/||A||/])
deskew_error * SUDI
ALIGN_DETECT_3
AUDI
A
SUDI(![/||A||/])
deskew_error * SUDI
ALIGN_ACQUIRED_1
enable_deskew ⇐ FALSE
AUDI
B
SUDI(![/||A||/])
!deskew_error
* SUDI(![/||A||/])
!deskew_error
* SUDI(![/||A||/])
!deskew_error
* SUDI(![/||A||/])
Note to Figure 1–127:
(1) This figure is from IEEE P802.3ae.
deskew_error * SUDI
deskew_error * SUDI
deskew_error * SUDI
ALIGN_ACQUIRED_2
AUDI
!deskew_error
* SUDI(![/||A||/])
C
SUDI(![/||A||/])
A
ALIGN_ACQUIRED_3
AUDI
!deskew_error
* SUDI(![/||A||/])
SUDI(![/||A||/])
B
ALIGN_ACQUIRED_4
AUDI
!deskew_error
* SUDI(![/||A||/])
SUDI(![/||A||/])
C
© June 2009 Altera Corporation
HardCopy IV Device Handbook Volume 3