SCEA exam has three parts:

1. Sun Certified Enterprise Architect for the Java Platform, Enterprise Edition 5 (Step 1 of 3) (CX-310-052)

2. Sun Certified Enterprise Architect for the Java Platform, Enterprise Edition 5: Assignment  (Step 2 of 3) (CX-310-301A)

3. Sun Certified Enterprise Architect for the Java Platform, Enterprise Edition 5: Essay (Step 3 of 3) (CX-310-062)

There is no prerequisite for SCEA exam. This is the top most certification by Sun for Java.

Click here to view topics covered in the exam (all three parts).