You should be able to download and install the Compiler 5 version of Kiel in order to compile and run the examples for the AD594x.
Here are some links that can help you with the process:
How can I install Compiler Version 5 for Keil vision 5 - Keil forum - Support forums - Arm Community
µVision User's Guide (arm.com)
Arm Compiler for Embedded FuSa