Datasheet

PCI Express Non-Transparent Bridge
Intel
®
Xeon
®
Processor C5500/C3500 Series
Datasheet, Volume 1 February 2010
162 Order Number: 323103-001
Table 84. Outgoing PCI Express Message Cycles with Respect to NTB
PCI Express
Transaction
Address Space
or Message
Reason for Issue
Outbound
Messages
Unlock
The NTB does not support lock cycles from either side of the NTB.
Primary side:
PCI Express-compliant software drivers and applications must be written to prevent the
use of lock semantics when accessing a Root Complex Integrated Endpoint.
If erroneous software is written and the lock sequence is sent, it will be followed by an
“Unlock” message to complete the lock sequence.
The NTB will pass the Unlock message from the primary side to the secondary side of the
bridge and then on the wire, to the remote host where it should be dropped. There is no
completion.
ASSERT_INTA
DEASSERT_INTA
ASSERT_INTB
DEASSERT_INTB
ASSERT_INTC
DEASSERT_INTC
ASSERT_INTD
DEASSERT_INTD
These messages are only used in NTB/RP configuration and are sent from the NTB
towards the RP when the local host writes any of the bits in the SDOORBELL and the INTx
interrupt mechanism is enabled.
INTA-D selection is based on setting of Section 3.20.2.18, “INTPIN: Interrupt Pin Register”
PME_Turn_Off
When the local host on the primary side of the NTB wants to initiate power removal on the
local system. SW on the local host sets the PME_TURN_OFF bit 5 in Section 3.19.4.20,
“MISCCTRLSTS: Misc. Control and Status Register” . HW will then clear bit 5 and set bit 48
PME_TO_ACK followed by sending an upstream PM_Enter_L23. See Section 8.0, “Power
Management” for details.
Note: The PME_turn_Off message is never sent on the wire to the link partner from the
local host to the remote host. The message and response are faked internal to
the NTB.
PME_TO_ACK
Upon receiving the PME_Turn_Off message on the secondary side of the NTB from the
remote host the NTB will return a PME_TO_ACK message to the remote host.
PM_PME
Propagate as an interrupt/general purpose event to the system. For details, refer to
Section 8.0, “Power Management” .
PM_ENTER_L1
(DLLP)
After remote host writes a state change request to the PMCS register Section 3.20.3.27,
“PMCSR: Power Management Control and Status Register” on the secondary side of the
NTB, the NTB then blocks subsequent TLP issue and wait for all pending TLPs to Ack.
Then, sends a PM_ENTER_L1 to the remote host.
Note: PM_ENTER_L1 is an outbound packet in the case of NTB/RP. For NTB/NTB case
this message will be seen as an outbound message from the DSD NTB and an
inbound message on the USD NTB.
PM_ENTER_L23
(DLLP)
After sending the PME_TO_Ack, the secondary side NTB sends the PM_ENTER_L23 to the
remote host to indicate to the remote host that it can remove power to the remote host.
Note: PM_ENTER_L23 is an outbound packet in the case of NTB/RP. For NTB/NTB case
this message will be seen as an outbound message from the DSD NTB and an
inbound message on the USD NTB.
PM_ACTIVE_STA
TE_REQUEST_L1
(DLLP)
After receiving acknowledgement from the link layer for the last TLP sent it can issue a
PM_ACTIVE_STATE_REQUEST_L1 to the Upstream device.
Note: PM_ACTIVE_STATE_REQUEST_L1 is an outbound packet in the case of NTB/RP.
For NTB/NTB case this message will be seen as an outbound message from the
DSD NTB and an inbound message on the USD NTB.
All Other
Messages
Silently discard if message type is type 1 and drop and log error if message type is type 0.