PCIe Devices - PLX Technology

PCIe Devices - PLX Technology PCIe Devices - PLX Technology

23.02.2014 Views

PCIe Packet Delineation or Framing n PCIe packets are detected or delineated at receiver by matching predefined symbols l l l Referred to as framing symbols Detection of predefined symbol sets determines where the first bit of the packet is and how the packet will be decoded – Received as a TLP or DLLP Beginning and ending packet symbols are required for all validated packets Physical/Data Link Header Transaction Layer Header Payload ECRC LCRC 11010110100100010101101001011010001011100010111010001011010010111101011101000101111001010000001011010110101 Device A PCIe Link Serial Packets Serial Packets Device B Packet Framing Symbols Copyright by Dashcourses, Inc. 2009 1-28

PCI Devices n n n PCI is based on a defined bus structure One or more PCI compliant devices attached to the PCI bus l Each PCI device may contain up to eight PCI functions – PCI function - a logical device • For example a sound card, a video card, or an IDE controller – Devices control 1-8 logical functions Devices may be a master or a target l l l Masters may initiate a bus transaction – Require a request/grant (REQ#/GNT#) pair wired to an arbiter for each master on the bus Targets may not initiate a bus transaction – Exception is a PCI-X target completing a split transaction response Devices attach to PCI busses by way of bridges Copyright by Dashcourses, Inc. 2009 1-29

PCI <strong>Devices</strong><br />

n<br />

n<br />

n<br />

PCI is based on a defined bus structure<br />

One or more PCI compliant devices attached to<br />

the PCI bus<br />

l<br />

Each PCI device may contain up to eight PCI functions<br />

– PCI function - a logical device<br />

• For example a sound card, a video card, or an IDE controller<br />

– <strong>Devices</strong> control 1-8 logical functions<br />

<strong>Devices</strong> may be a master or a target<br />

l<br />

l<br />

l<br />

Masters may initiate a bus transaction<br />

– Require a request/grant (REQ#/GNT#) pair wired to an arbiter<br />

for each master on the bus<br />

Targets may not initiate a bus transaction<br />

– Exception is a PCI-X target completing a split transaction<br />

response<br />

<strong>Devices</strong> attach to PCI busses by way of bridges<br />

Copyright by Dashcourses, Inc. 2009<br />

1-29

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