15.5.1.2 Custom Configuration
If a custom configuration of the Ethernet PHY is required, the application can program the configuration registers after reset. The steps for custom configuration are as follows:
- To hold the PHY from transmitting energy on the line during configuration, set the PHYHOLD bit to 1 in the EMACPC register.
- Enable the clock to the PHY module by writing 0x0000.0001 to the Ethernet PHY Run Mode Clock Gating Control (RCGCEPHY) register at offset 0x630. When the R0 bit reads as 1 in the PREPHY register at System Control offset 0xA30, continue initialization.
- Enable power to the Ethernet PHY by setting the P0 bit in the PCEPHY register at System Control offset 0x930. When the R0 bit reads as 1 in the PREPHY register at System Control offset 0xA30, the PHY registers are ready for programming.
- Once the Ethernet PHY Peripheral Ready (PREPHY) register reads 0x0000.0001, software can write the EMACPC register with the required value.
- After software configuration is complete, the application must set the DONE bit in the Ethernet PHY Configuration 1 (EPHYCFG1) register at offset 0x009.
NOTE
If a software reset is asserted to the PHY afterwards through the SREPHY register, the custom configuration is lost and the steps described above must be repeated.