
IDT PCI-to-PCI Bridge Registers
PES32NT24xG2 User Manual
20 - 21
January 30, 2013
Notes
PCIELCTL - PCI Express Link Control (0x050)
Bit
Field
Field
Name
Type
Default
Value
Description
1:0
ASPM
RW
0x0
Active State Power Management (ASPM) Control.
This field controls the level of ASPM supported by the link.
The initial value corresponds to disabled.
0x0 - (disabled) disabled
0x1 - (l0s) L0s enable entry
0x2 - (l1) L1 enable entry
0x3 - (l0sl1) L0s and L1 enable entry
Note that “L0s enable entry” corresponds to the transmitter
entering L0s (the receiver supports this function and is not
affected by this setting).
When a port operates in a multi-function mode, only capa-
bilities enabled in all functions of the port are enabled for
the port as a whole (e.g., L0s is enabled for the port when
all functions of the port have L0s enabled in this field).
It is recommended, though not required, that software pro-
gram the same value in this field for all functions of the port.
2
Reserved
RO
0x0
Reserved field.
3
RCB
RO
0x0
Read Completion Boundary.
This field is not applicable and is hardwired to zero.
4
LDIS
Upstream
Port:
RO
Down-
stream
Switch
Port:
RW
0x0
Link Disable.
When set in a downstream switch port, this bit disables the
link.
Writes to this bit are immediately reflected in the value of
the bit, regardless of the actual link state.
This bit is not applicable for an upstream port and is hard-
wired to zero.
5
LRET
Upstream
Port:
RWL
Down-
stream
Switch
Port:
RW
0x0
Link Retrain.
Writing a one to this field initiates Link retraining by direct-
ing the Physical Layer LTSSM to the Recovery state. This
field always returns zero when read.
It is permitted to set this bit while simultaneously modifying
other fields in this register.
When this bit is set and the LTSSM is already in the Recov-
ery or Configuration states, all modifications that affect link
retraining are applied in the subsequent retraining. Else, if
the LTSSM is not in the Recovery or Configuration states,
modifications that affect link retraining are applied immedi-
ately.
For compliance with the PCI Express Base Specification,
this bit has no effect on the upstream port when the
REGUNLOCK bit is cleared in the SWCTL register. In this
mode the field is hardwired to zero. When the REGUN-
LOCK bit is set, writing a one to the LRET bit initiates link
retraining on the upstream port after a programmed delay.
The switch always returns a completion for the request that
set this bit, before the effect of this bit is applied.
Summary of Contents for PCI Express 89HPES32NT24xG2
Page 20: ...IDT Table of Contents PES32NT24xG2 User Manual x January 30 2013 Notes...
Page 24: ...IDT List of Tables PES32NT24xG2 User Manual xiv January 30 2013 Notes...
Page 28: ...IDT List of Figures PES32NT24xG2 User Manual xviii January 30 2013 Notes...
Page 56: ...IDT PES32NT24xG2 Device Overview PES32NT24xG2 User Manual 1 20 January 30 2013 Notes...
Page 100: ...IDT Switch Core PES32NT24xG2 User Manual 4 22 January 30 2013 Notes...
Page 128: ...IDT Failover PES32NT24xG2 User Manual 6 4 January 30 2013 Notes...
Page 148: ...IDT Link Operation PES32NT24xG2 User Manual 7 20 January 30 2013 Notes...
Page 164: ...IDT SerDes PES32NT24xG2 User Manual 8 16 January 30 2013 Notes...
Page 170: ...IDT Power Management PES32NT24xG2 User Manual 9 6 January 30 2013 Notes...
Page 196: ...IDT Transparent Switch Operation PES32NT24xG2 User Manual 10 26 January 30 2013 Notes...
Page 244: ...IDT SMBus Interfaces PES32NT24xG2 User Manual 12 40 January 30 2013 Notes...
Page 247: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 3 January 30 2013 Notes...
Page 248: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 4 January 30 2013 Notes...
Page 330: ...IDT Switch Events PES32NT24xG2 User Manual 16 6 January 30 2013 Notes...
Page 342: ...IDT Multicast PES32NT24xG2 User Manual 17 12 January 30 2013 Notes...
Page 344: ...IDT Temperature Sensor PES32NT24xG2 User Manual 18 2 January 30 2013 Notes...
Page 384: ...IDT Register Organization PES32NT24xG2 User Manual 19 40 January 30 2013...
Page 492: ...IDT Proprietary Port Specific Registers PES32NT24xG2 User Manual 21 44 January 30 2013 Notes...
Page 588: ...IDT NT Endpoint Registers PES32NT24xG2 User Manual 22 96 January 30 2013 Notes...
Page 710: ...IDT JTAG Boundary Scan PES32NT24xG2 User Manual 25 12 January 30 2013 Notes...
Page 743: ...IDT Usage Models PES32NT24xG2 User Manual 26 33 January 30 2013 Notes...
Page 744: ...IDT Usage Models PES32NT24xG2 User Manual 26 34 January 30 2013 Notes...