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DM 648

adnan khurshid
Intellectual 255 points
Other Parts Discussed in Thread: TMS320C6424, TMS320DM647

hello all,

i am looking for board DM648, initially i was working on TMS320C6424. i was given the task to complete the full duplex communication. i was receiving LAN data from E MAC of evm6424 and transmitting it on LAN back through a daughter card. i have two RJ45 for full duplex communication, one on evm6424 and other on the daughter card.

the problem was that data transfer between evm6424 and daughter card was through SPI. SPI has a max data transfer rate of 15 Mbps, which is insufficient for 100 Mbps LAN transfer.

 

now i as looking at DM648, which has two ports. i have some queries before i purchase new board...

does its both ports or say G Macs work simultaneously?

had anyone did the job as i want to do?

does this board solves my problem of real time traffic, picking all packets from one port and transmitting to other port and vice versa without delay?

regards

adnan khurshid

  • 0
    TI__Guru 64460 points

    adnan khurshid said:

    now i as looking at DM648, which has two ports. i have some queries before i purchase new board...

    does its both ports or say G Macs work simultaneously?

    The 2 RJ45 connectors on the DM648 EVM are connected to the 2 SGMII interfaces on the DM648 (1 RJ45 for 1 SGMII interface) through a Ethernet PHY device.  So, yes they can be active simultaneously.

     

    adnan khurshid said:

    had anyone did the job as i want to do?

    I can't say as I don't have any first hand knowledge.

     

    adnan khurshid said:

    does this board solves my problem of real time traffic, picking all packets from one port and transmitting to other port and vice versa without delay?

    Are you asking if this acts like a switch and can be setup to route packets coming in from one interface and send them without CPU intervention to the other interface?  Yes, the DM648 implements a 3-port switch.
    Regarding "without delay" I would say that there would be some delay, but nothing introduced by the CPU.
    However, if the CPU is required to inspect each packet, determine if it should go to the other port, or do higher level functionality, etc. then no, delay will be introduced.

  • 0 in reply to BrandonAzbell
    Intellectual 255 points

    hello,

    what should i understand from this, both ports can receive LAN packets through SGMII at the same time???

    my job is to complete full duplex communication. which means that both ports are receiving at the same time and transmitting at the same time also.

    also i have to receive packets from one port, the CPU is required to inspect each packet, determine if it should go to the other port or not, and then send through 2nd port ans vice versa. there is delay in processing as it puts the packet into DDR memory and then process and transmit. thats why i am curious about delay so it will not miss a single packet.


    regards
    akqureshi

  • 0 in reply to adnan khurshid
    Intellectual 720 points

    May I recommend you review the follow document?:

    TMS320DM647/DM648 DSP 3 Port Switch (3PSW) Ethernet Subsystem User's Guide (Rev. A) (spruf57a.htm, 8 KB)

    There is some delay and it is highly dependent on how you set up the E-switch fifos and other components.  I worked with a person whose job was to verify the DM648 Eswitch, and I know it is not exactly trivial.  But it does work well when configured correctly.  Also, if you're using DSP Bios, you will want to get TI's TCI/P Stack Developer's kit (formerly known as the Network Developer's Kit) to make it easier to put the Ethernet switch on a LAN.

     

    Good Luck.