Notes
PES16T4AG2 User Manual
3 - 1
May 23, 2013
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Chapter 3
Link Operation
Introduction
Link operation in the PES16T4AG2 adheres to the PCI Express 2.0 Base Specification, supporting
speeds of 2.5 Gbps and 5.0 Gbps. The PES16T4AG2 contains six x4 ports which may be merged in pairs
to form x8 ports. The default link width of each port is x4 and the SerDes lanes are statically assigned to a
port. A full link retrain is defined as retraining of a link that transitions through the Detect LTSSM state.
Polarity Inversion
Each port of the PES16T4AG2 supports automatic polarity inversion as required by the PCIe specifica-
tion. Polarity inversion is a function of the receiver and not the transmitter. The transmitter never inverts its
data. During link training, the receiver examines symbols 6 through 15 of the TS1 and TS2 ordered sets for
inversion of the PExAP[n] and PExAN[n] signals. If an inversion is detected, then logic for the receiving lane
automatically inverts received data. Polarity inversion is a lane and not a link function. Therefore, it is
possible for some lanes of link to be inverted and for others to not be inverted.
Lane Reversal
The PCIe specification describes an optional lane reversal feature. The PES16T4AG2 offers limited
support for the automatic lane reversal feature outlined in the PCIe specification. Lane reversal mapping for
the various configurations supported by the PES16T4AG2 are illustrated in Figures 3.1and 3.2.
Figure 3.1 Unmerged Port Lane Reversal
PExRP[0]
PExRP[1]
PExRP[2]
PExRP[3]
PES16T4AG2
lane 0
lane 1
lane 2
lane 3
(a) x4 Port without lane reversal
PExRP[0]
PExRP[1]
PExRP[2]
PExRP[3]
PES16T4AG2
lane 3
lane 2
lane 1
lane 0
(b) x4 Port with lane reversal
PExRP[0]
PExRP[1]
PExRP[2]
PExRP[3]
PES16T4AG2
lane 0
lane 1
(a) x2 Port without lane reversal
PExRP[0]
PExRP[1]
PExRP[2]
PExRP[3]
PES16T4AG2
lane 1
lane 0
(b) x2 Port with lane reversal
PExRP[0]
PExRP[1]
PExRP[2]
PExRP[3]
PES16T4AG2
lane 0
(a) x1 Port without lane reversal
PExRP[0]
PExRP[1]
PExRP[2]
PExRP[3]
PES16T4AG2
lane 0
(b) x1 Port with lane reversal
Содержание 89HPES16T4AG2
Страница 8: ...IDT PES16T4AG2 User Manual 6 May 23 2013 Notes...
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Страница 14: ...IDT List of Tables PES16T4AG2 User Manual vi May 23 2013 Notes...
Страница 16: ...IDT List of Figures PES16T4AG2 User Manual viii May 23 2013 Notes...
Страница 20: ...IDT Register List PES16T4AG2 User Manual xii May 23 2013 Notes...
Страница 72: ...IDT SMBus Interfaces PES16T4AG2 User Manual 5 20 May 23 2013 Notes...
Страница 76: ...IDT Power Management PES16T4AG2 User Manual 6 4 May 23 2013 Notes...
Страница 156: ...IDT Configuration Registers PES16T4AG2 User Manual 8 74 May 23 2013 Notes...