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Altera_Forum
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15 years ago

Slow PCIe cycles

I'm seeing very slow PCIe cycles from a PPC master to Altera FPGA Avalon MM slave peripherals. Typical times are 4us for a read and 7us for a write - which seem extremely pedestrian to me! Does...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

Hello DSL, Did you get your PCIe problem resolved?

I have inherited a project that inlcudes a Cycone IV GX part acting as a bridge between PCIe and an 8 bit A/D bus.

A single byte read cycle takes less than 200ns on the A/D bus, but 3.5 us on the PCIe end.

Any tips on where to begin looking to improve the PCIe throughput would be appreciated.

The Altera part is connected via PCIe to an ATOM based system running Windows 7.