Ethernet Switch

[hswqs]

I want to use CPU to read and write the internal registers of BCM53128. Using MDC/MDIO.

How to put BCM53128 MDC/MDIO in slave mode?

Thanks!

Jack Wen

7.4 2018

[ryanl · Accepted solution]

Hi Jack,

For BCM53128 MDC/MDIO in slave mode by external CPU/host access,

- use Pseudo-PHY via MDC/MDIO for internal Switch registers access.

- use actual PHY address via MDC/MDIO for internal GPHY registers access.

Please double check with BCM53128 datasheet Section4: Programming Interface: MDC/MDIO Interface: PseudoPHY section descriptions for the detail.

1. strap pin "CPU_EEPRO_SEL" needs set to 1 for Pseudo PHY access.

2. The external CPU/host SW please follow datasheet PseudoPHY section for PseudoPHY MII regstier definitions and read/write flow chart for the PseudoPHY access BCM53128 internal Switch registers, the PHY address is 0x1E.

3. For BCM53128 internal GPHY registers access by external CPU/host via MDC/MDIO, please use actual internal PHY address by MDC/MDIO read/write protocol.

BCM53128 internal GPHY address are as below which be described in datasheet.

- PHY address for Port 0 is 0

- PHY address for Port 1 is 1

- PHY address for Port 2 is 2

- PHY address for Port 3 is 3

- PHY address for Port 4 is 4

- PHY address for Port 5 is 5

- PHY address for Port 6 is 6

- PHY address for Port 7 is 7

Thanks,

Ryan

[hswqs]

Hi ryanl, Thanks.

Jack Wen