This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

LPC1788 EMAC

Hello,

I'm using LCP1788 with a ethernet PHY.

The problem is that some times it receives from PHY a ethernet frame with most part of it filled with 0x55.

I'm using wireshark for comparing between transmited and received frame. And most part of the time the received frame is equal to the transmited from PC but sometimes the LPC1788 receives a frame filled with 0x55.

Does anyone have a clue about this?

Thank you.

Henrique

Parents
  • hi, I get the solution,setting the options for target used Keil MDK:
    Memory Assignment:
    default: IROM1:start:0x0 size:0x80000
    default: IRAM2:start:0x20000000 size:0x8000

    I find as explained below:
    In case the ethernet code is making use of DMA, then the buffer memory must be in the RAM region supported by the DMA controller. Note that the processor have multiple memory controllers, to allow concurrent access to different RAM regions - so a DMA transfer can happen without being affected by the processor core reading/writing normal variables.

    best regards!

Reply
  • hi, I get the solution,setting the options for target used Keil MDK:
    Memory Assignment:
    default: IROM1:start:0x0 size:0x80000
    default: IRAM2:start:0x20000000 size:0x8000

    I find as explained below:
    In case the ethernet code is making use of DMA, then the buffer memory must be in the RAM region supported by the DMA controller. Note that the processor have multiple memory controllers, to allow concurrent access to different RAM regions - so a DMA transfer can happen without being affected by the processor core reading/writing normal variables.

    best regards!

Children
No data