3.11. Configuration Registers
Write operations to a read-only register field have no effect. Read operations that address a reserved register return an unspecified result. Write operations to reserved registers have an undefined effect. Accesses to registers that do not exist in your IP core variation, or to register bits that your IP core variation does not define, have an unspecified result. Consider these registers and register bits reserved. Although you can only access registers in 32-bit read and write operations, do not attempt to write or ascribe meaning to values in undefined register bits.
- PMA and FEC Direct PHY soft CSR registers
- FHT PMA registers
- FGT PMA registers