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ramsoffer_123's avatar
ramsoffer_123
Icon for Occasional Contributor rankOccasional Contributor
3 years ago

evb cyclon v soc kit ddr3 throughput measurement is low

hi everyone, Im trying to read and write to ddr3 on the EVB cyclone v board. im using the ddr controller. i created read and write components to the controller through the avalon bus: ...
AdzimZM_Altera's avatar
AdzimZM_Altera
Icon for Regular Contributor rankRegular Contributor
3 years ago

Hi Ram,


There is no information on the advantage between the unidirectional and bidirectional ports.

But what I can see that the bidirectional port can guarantee the operation ordering.

  • The requests arriving at a port are executed in order in which they are received.
  • The requests arriving at different ports have no guaranteed order of service.


But the multi-port can have a scheduling by the priority and weight of a port.

  • Any transactions of priority seven will always be scheduled before transactions of priority six or lower.
  • If two ports have same priority value, the weight value will be updated.
    • Let say the weight values have been set to 4 and 6.
    • The port with a weight of 4 will receive 40% of bus bandwidth.
    • The port with a weight of 6 will receive 60% of bus bandwidth.
    • Assuming 100% total available bus bandwidth.


You can try to change the priority value and weight value of the ports and see if that improve the efficiency.

Also try to increase the Maximum Avalon-MM burst length to higher value.


Regards,

Adzim