UART1 and the External Memory Interface on ADuC7129

It seems that UART1's RX and TX lines are multiplexed with the MSB's of the external memory interface on the ADuC7129. I am going under the assumption that if I want to use UART1, I can still use an 8-bit data bus and perhaps a 12-bit address bus with the remaining memory interface pins. Are there any considerations or pitfalls I should be aware of in such a configuration?