CBFD Debug Screen 1
If the game would ever crash(pretty rare), either by glitches or using Gameshark codes, then it has crashed. But if the Debug Mode cheat XFYHIJERPWAL_IELWZS was entered at the Options screen (or use 810EA132 FFFF, it enables the debug cheat, with access to all chapters in chapter mode) in the bar before the game crashed the game will start displaying numbers and letters of what at first seems to be random nonsense. Wait for a moment, and if “PRESS BUTTON” appears on screen, then it worked. Pressing A or B advances to the “MAIN MENU” screen. Once in there, tilt the control stick up or down to select a option. A to advance to the debug screen selected, and B to go back to Main Menu. Emulators won’t redraw the screen if the game has crashed, but if you save a state of the game at this point while the game still appears to be frozen, and then reloading it will make it appear(everything on the screen will be black, except the letters and numbers). Alternatively, you can use 81000002 1001. Turn the cheat on at any point in the game, and it’ll freeze up, making it easy enough to enter the debugger.

                                                     MAIN MENU:
                                  CBFD Debug Screen 2
No need to explain this screen in extreme detail. The text on the bottom shows the date the final build was compiled on, which reads “Jan 31 2001 13:29:42″, and the version number is 19. In the NTSC version's crash debugger, the compilation date reads "Dec 19 2000 09:57:42", and the version number is 163. Hmm.. The PAL game seemed to not have received much testing, nor any major changes in content. Did Rare went lazy with the PAL conversion??

                                  CBFD Debug Screen 3
Self-explationary, shows the type of cause that made the game crash, as well as the Register threads. pressing c-right/left will display two more screens. What is being filled in there depends on at what point in the game the player were at the time of the crash.

Additonal screens:
   CBFD Debug Screen 4   CBFD Debug Screen 5

                                   CBFD Debug Screen 6
Shows the stack. Up and Down on Control stick scrolls through the stack, showing the newest value being pushed up on top, withthe older values being pushed down, freeing them from memory. C buttons up and down do the same thing, but only one line at a time for each press.

Depending on the type of crash, the debugger will either say “HOSTDEBUG”, or “RETRYCODE”.. RETRYCODE only returns you to the debugger without doing anything else, as the game has crashed. HOSTDEBUG i think once served an important role during development, as it was used for debugging purposes by the developers at Rare, to test out various things without having to go through the whole game. According to recent videos on youtube, there is more to the debugger than initially thought. There was alot more options, like Memory, Memmap, Cameras, and alot more which by now has been reduced to only 3 in the retail, namely Registers, Stack, and Host Debug/Retry code.