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Ethernet Switch

Occasional Visitor
Posts: 1
Registered: ‎01-10-2018

Clarification required on configuring BCM53115 port-5 WAN port mode to SERDES Fibermode

Dear Broadcom,

We need help in accessing WAN (Port-5) registers in BCM53115SKFBG Robo switch.


In our design, the SerDes (WAN interface Port-5) of the Switch BCM53115 is used for interfacing with other cards through Backplane. The Bootstrap is configured with GMII_CTRL =0 for this in our design. Port-0&1 are used as Copper interface ports and IMP port in RGMII mode used for interfacing with Processor.


We are observing the problem of Ethernet Link is not coming UP through this SerDes interface (Port-5), when it is interfaced to another card with the same Switch (BCM53115, SerDes WAN interface Port-5).

But we observe that the Link is coming UP by default, when we interface the same Card with another card where BCM5482S is used for the SerDes interface. We would like to access the Page 15h: Internal SerDes Port (Port 5) Registers for verifying the configuration and status through PseudoPHY access using MDC/MDIO interface. But we are not able to access any of these registers in Page 15. Please note that we are able to access Page-0 and Page-31 registers through the same PsuedoPHY interface for controlling LEDs and Port based VLAN configurations.

Please let us know your suggestion for finding the issue in getting the SerDes Link UP between the cards, which use the same Switch port-5 and let us know the procedure to access the SerDes registers of Page-15.



Posts: 300
Registered: ‎02-15-2016

Re: Clarification required on configuring BCM53115 port-5 WAN port mode to SERDES Fibermode


We are double checking your question and will reply it.

Please double check your pseudo phy access (MDC/MDIO) and need to follow below:


For BCM53115, if using MDC MDIO to access BCM53115 registers.
1. For internal Serdes PHY (port 5) and Copper GPHY ports(port 0 to 4), please use MDC/MDIO direct access to those PHY registers : Serdes port PHY MDC/MDIO  address : 5; Copper  GPHY MDC/MDIO address is 0 to 4 . Internal Serdes also has block address . The default block address is 0. If you want to access other block registers , you need to change block address register value first.

2. For all other register (all the regs not list in item 1 #) , you must use Pseudo Phy ( PHY address :0x1e (that is 30)) to access them indirectly. Please refer to our data sheet.




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