Is Institute Training Mandatory for appearing ABAP Certification Exam

Dear Experts,

I have an experience of 1 year in SAP ABAP with 1 end to end implementation project.

Now i want to get certified.

I have read several post about SAP ABAP Certification.

Bit i m not clear whether it is mandatory to attain training from institutes (like siemens, delphi )

I dont want to appear for institutional training.

Can i give exam directly?

Plz reply !!!

thanks and Regards,

Apoorv Sharma