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Altera_Forum's avatar
Altera_Forum
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15 years ago

Extension cable for PCIe

Hi, I have a Arria II GX dev kit and want to use the PCIe interface. I am planning to connect it using an extension cable instead of connecting it directly on the mother board. Any suggestions...
Altera_Forum's avatar
Altera_Forum
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15 years ago

Internal PCIe interfaces are using a common Refclk architecture, as far as I understand. By specification, the data/clock transport delay delta t1 must not exceed 12 ns (see PCIe Base-Specification V2.0, 4.3.7.2.2. Common Refclk Architecture). Considering various on chip and motherboard wiring delays, a 1 m extension cable can't keep it. I don't know however, if the parameter is critical. Apart from this problem, I'm only aware of short (0.1 - 0.2 m extension cables) available as retail products.

In addition, you have to keep the attenuation and other signal quality parameters.