PS2 Games on PS3; Entering cheats?

The game I’m trying to input cheats on is Mat Hoffman’s Pr BMX 2.
Originally made for Dreamcast/PS2, I’m trying to use it on my PS3 and not being able to use any cheats.
Any ideas on how to enter them?
Answer #1
i played San andreas on Ps3, cheats where the same why would they be different ?