ADUC7126 UART1 & External memory

Hi!
I have a problem with MCU ADUC7126.
I config pin P4.0 as SIN1 and P4.1 as SOUT1 in GP4CON:
0xFFFFF410: 0x00000011
It works, I see recieved and transmit UART1 data.

When I config pin P2.3 as AE (external memory) in GP2CON:
0xFFFFF408: 0x00002022
I read/write external memory data, but I doesn`t recieved data on UART1.
Could you tell me please, what I do wrong?