
IDT Link Operation
PES32NT24xG2 User Manual
7 - 13
January 30, 2013
Notes
A port configured in NT function mode or NT with DMA function mode initiates L0s entry when all of the
conditions listed below are met:
–
L0s ASPM is enabled via the PCIELCTL register of all functions in the port.
–
The following conditions are met for the amount of time specified above:
• The port has no TLPs to transmit on the link (i.e., the port’s EFB is empty) or there are no avail-
able flow control credits to transmit a TLP.
• The port has no DLLPs pending for transmission.
A port configured in upstream switch port with NT function mode or upstream switch port with NT and
DMA function mode initiates L0s entry when the L0s entry conditions are met for all of its functions (i.e., L0s
entry conditions for the PCI-to-PCI bridge, NT, and DMA functions are met):
–
L0s ASPM is enabled in the PCIELCTL register of all functions in the port.
–
The following conditions are met for the amount of time specified above
1
:
• The receive lanes of all of the downstream switch ports in the switch partition (i.e., associated
with the PCI-to-PCI bridge function) which are not in a low power state (i.e., D3) and whose link
is not down are in the L0s state.
• The port has no TLPs to transmit on the link (i.e., the port’s EFB is empty) or there are no avail-
able flow control credits to transmit a TLP.
• The port has no DLLPs pending for transmission.
L0s Exit Conditions
The transmit side L0s exit conditions depend on the port’s operational mode. A port configured in
upstream switch port mode initiates exit from L0s when either of the conditions listed below is met:
–
The port has a TLP or DLLP scheduled for transmission on the link.
–
A downstream switch port in the switch partition has initiated exit from L0s.
A port configured in downstream switch port mode initiates exit from L0s when either of the conditions
listed below is met:
–
The port has a TLP or DLLP scheduled for transmission on the link.
–
The upstream port in the switch partition has initiated exit from L0s.
A port configured in NT function mode or NT with DMA function mode initiates exit from L0s when the
condition listed below is met:
–
The port has a TLP or DLLP scheduled for transmission on the link.
Finally, a port configured in upstream switch port with NT function mode or upstream switch port with NT
and DMA function mode initiates exit from L0s when either of the conditions listed below is met:
–
The port has a TLP or DLLP scheduled for transmission on the link.
–
A downstream switch port in the switch partition associated with the PCI-to-PCI bridge function
has initiated exit from L0s.
L1 ASPM
L1 entry/exit is initiated by downstream link components (i.e., upstream ports) and affects both direc-
tions of the link. Upstream link components (i.e., downstream switch ports) accept or reject L1 entry
requests from the link partner.
L1 Entry Conditions
The PES32NT24xG2 downstream switch ports may accept or reject L1 entry requests sent by the link
partner. A port configured in downstream switch port mode accepts L1 entry requests when all of the condi-
tions listed below are met. Otherwise, the L1 entry request is rejected.
–
L1 ASPM is enabled via the port’s PCIELCTL register.
–
The port has no TLPs pending for transmission on the link (i.e., the port’s EFB is empty).
–
The port has no ACK or NAK DLLPs pending for transmission.
1.
Note that there is a single L0ET timer for both functions of the port.
Содержание PCI Express 89HPES32NT24xG2
Страница 20: ...IDT Table of Contents PES32NT24xG2 User Manual x January 30 2013 Notes...
Страница 24: ...IDT List of Tables PES32NT24xG2 User Manual xiv January 30 2013 Notes...
Страница 28: ...IDT List of Figures PES32NT24xG2 User Manual xviii January 30 2013 Notes...
Страница 56: ...IDT PES32NT24xG2 Device Overview PES32NT24xG2 User Manual 1 20 January 30 2013 Notes...
Страница 100: ...IDT Switch Core PES32NT24xG2 User Manual 4 22 January 30 2013 Notes...
Страница 124: ...IDT Switch Partition and Port Configuration PES32NT24xG2 User Manual 5 24 January 30 2013 Notes...
Страница 128: ...IDT Failover PES32NT24xG2 User Manual 6 4 January 30 2013 Notes...
Страница 148: ...IDT Link Operation PES32NT24xG2 User Manual 7 20 January 30 2013 Notes...
Страница 164: ...IDT SerDes PES32NT24xG2 User Manual 8 16 January 30 2013 Notes...
Страница 170: ...IDT Power Management PES32NT24xG2 User Manual 9 6 January 30 2013 Notes...
Страница 196: ...IDT Transparent Switch Operation PES32NT24xG2 User Manual 10 26 January 30 2013 Notes...
Страница 244: ...IDT SMBus Interfaces PES32NT24xG2 User Manual 12 40 January 30 2013 Notes...
Страница 247: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 3 January 30 2013 Notes...
Страница 248: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 4 January 30 2013 Notes...
Страница 330: ...IDT Switch Events PES32NT24xG2 User Manual 16 6 January 30 2013 Notes...
Страница 342: ...IDT Multicast PES32NT24xG2 User Manual 17 12 January 30 2013 Notes...
Страница 344: ...IDT Temperature Sensor PES32NT24xG2 User Manual 18 2 January 30 2013 Notes...
Страница 384: ...IDT Register Organization PES32NT24xG2 User Manual 19 40 January 30 2013...
Страница 492: ...IDT Proprietary Port Specific Registers PES32NT24xG2 User Manual 21 44 January 30 2013 Notes...
Страница 588: ...IDT NT Endpoint Registers PES32NT24xG2 User Manual 22 96 January 30 2013 Notes...
Страница 710: ...IDT JTAG Boundary Scan PES32NT24xG2 User Manual 25 12 January 30 2013 Notes...
Страница 743: ...IDT Usage Models PES32NT24xG2 User Manual 26 33 January 30 2013 Notes...
Страница 744: ...IDT Usage Models PES32NT24xG2 User Manual 26 34 January 30 2013 Notes...