WG82574L S LBA8 Intel, WG82574L S LBA8 Datasheet - Page 33

• Manufacturer Part Number: WG82574L S LBA8
• Manufacturer: Intel

Specifications of WG82574L S LBA8

• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: 0C to 85C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 64
• Lead Free Status / RoHS Status: Compliant

Interconnects—82574 GbE Controller
3.1.3.9
3.1.3.10
3.1.4
3.1.4.1
Error Forwarding
If a Transaction Layer Protocol (TLP) is received with an error-forwarding trailer, the
packet is dropped and not delivered to its destination. The 82574 does not initiate any
additional master requests for that PCI function until it detects an internal reset or
software. Software is able to access device registers after such a fault.
System logic is expected to trigger a system-level interrupt to inform the operating
system of the problem. The operating system can then stop the process associated
with the transaction, re-allocate memory instead of the faulty area, etc.
Master Disable
System software can disable master accesses on the PCIe link by either clearing the
PCI Bus Master bit or by bringing the function into a D3 state. From that time on, the
82574 must not issue master accesses for this function. Due to the full-duplex nature
of PCIe, and the pipelined design in the 82574, it might happen that multiple requests
from several functions are pending when the master disable request arrives. The
protocol described in this section insures that a function does not issue master requests
to the PCIe link after its master enable bit is cleared (or after entry to D3 state).
Two configuration bits are provided for the handshake between the device function and
its driver:
Software Note:
Flow Control
Flow Control Rules
The 82574 only implements the default Virtual Channel (VC0). A single set of credits is
maintained for VC0.
• PCIe Master Disable bit in the Device Control (CTRL) register - When the PCIe
• PCIe Master Enable Status bits in the Device Status register - Cleared by the 82574
Master Disable bit is set, the 82574 blocks new master requests, including
manageability requests. The 82574 then proceeds to issue any pending requests by
this function. This bit is cleared on master reset (Internal Power On Reset all the
way to a software reset) to enable master accesses.
when the PCIe Master Disable bit is set and no master requests are pending by the
relevant function, set otherwise.
— The software device driver sets the PCIe Master Disable bit when notified of a
— The PCIe Master Disable bit must be cleared to enable a master request to the
pending master disable (or D3 entry). The 82574 then blocks new requests and
proceeds to issue any pending requests by this function. The software device
driver then polls the PCIe Master Enable Status bit. Once the bit is cleared, it is
guaranteed that no requests are pending from this function. The software
device driver might time out if the PCIe Master Enable Status bit is not cleared
within a given time.
PCIe link. This can be done either through reset or by the software device
driver.
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