breakpoint : reserved opcode : index :

Description
Opcode 0xCA (202) is a reserved opcode with the mnemonic breakpoint. This opcode is reserved for internal use by a Java implementation, and must not appear in any class file - methods containing a breakpoint will fail verification.

In Sun's implementation, the breakpoint opcode is used internally as a place-holder indicating a point in a method where control should pass to the Java debugger (jdb).
See also
impdep1 impdep2.
Stack
Before After
... ...
Bytecode
Type Description
u1 breakpoint opcode = 0xCA (202)