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BCM5389 STP Requirements

  • 1.  BCM5389 STP Requirements

    Posted 09-18-2019 07:47 AM
    Dear All,

    I'm using BCM5389 chip in our Projects.

    We need to enable and disable STP on the specific ports only. Kindly let me know the required registers to enable and disable the stp on the specific ports. Also, let me know my only enabling the specific registers are enough for enabling/disabling the stp on the ports.

    Thanks,
    Mohan


  • 2.  RE: BCM5389 STP Requirements

    Posted 09-20-2019 06:57 AM

    Hi Mohan,

    BCM5389 support STP (spanning tree) and able to recognize BPDU packet and forward it to external CPU for STP SW protocol operation.

    Please be note the STP function is handling by external CPU SW STP protocol, not by chip.

    From BCM5389 chip point of view, it just supports BPDU packet forwarding to external CPU and register to allow external CPU to change each port STP state.

    1. Only Port Control Register(0x00: 0x00-0x07) required to configure by external CPU for STP
    • Write to Port Control Register(0x00: 0x00-0x07) bit[7:5] for STP state of each port
    1. BCM5389 IMP port which is connecting with external CPU needs configure in managed mode
    • Set Reg(0x00: 0x08)=0x1c
    • Set Reg(0x00: 0x0b)=0x07
    • Set Reg(0x00: 0x0e)=0x8b to force link up IMP port at 1000Mbps for example
    • Set Reg(0x02: 0x00)=0x82

     

    Thanks,

    Ryan



    ------------------------------
    Master R&D Applications Engineer
    Broadcom
    ------------------------------



  • 3.  RE: BCM5389 STP Requirements

    Posted 09-20-2019 07:39 AM
    Hi Ryan,

    Thank you for providing the registers.

    Is there any open source for handling the STP on the external CPU side?


  • 4.  RE: BCM5389 STP Requirements

    Posted 09-20-2019 10:47 AM
    Hi Mohan,
    I need to double check and will get back you early next week.

    Thanks,
    Ryan

    ------------------------------
    Master R&D Applications Engineer
    Broadcom
    ------------------------------



  • 5.  RE: BCM5389 STP Requirements

    Posted 09-24-2019 02:42 AM
    Hi Mohan,
    Please find the below link of STP open source for your reference.

    https://www.tldp.org/HOWTO/BRIDGE-STP-HOWTO/index.html

    https://elixir.bootlin.com/linux/latest/source/net/bridge/br_stp.c


    Thanks,
    Ryan

    ------------------------------
    Master R&D Applications Engineer
    Broadcom
    ------------------------------



  • 6.  RE: BCM5389 STP Requirements

    Posted 09-25-2019 08:56 AM
    Dear Ryan,

    Thank you for share the required info. Let me make use of it.