MAC Address and ColdFire MFC5329
I am assuming you meant MCF5329 (not MFC5329)

According to the MCF5329 data sheet, there are both an SSI (synchronous serial interface) and an I2C module, either of which could be used to access a small external EEPROM.

If you do not already have a block of MAC addresses (or if you do not wish to go to the trouble of programming the EEPROM), Microchip offers I2C EEPROMs with pre-programmed EUI-48 or EUI-64 addresses: 
http://ww1.microchip.com/downloads/en/DeviceDoc/20002124E.pdf

MAC addresses are sometimes stored in a reserved location in non-volatile program memory (such as FLASH memory). Since the MCF5329 has no internal non-volatile memory, you will need to look to where the program memory is stored to see if this is an option. If you go this route, take care that any bootloader or other form of software/firmware update will not overwrite the MAC address.

Some microcontrollers even have a small section of OTP (one-time programmable) memory for uses such as this, although it appears that the MCF5329 does not.