How can compiler produce opcode that is illegal ?

[#1]

Infineon TC29x documentation says that executing illegal opcode causes a trap.

How can compiler produce code with illegal opcode? We're using Windriver Compiler / Assembler / Linker? Shouldn't illegal opcode cause a assembler or compiler error ?

[cwunder]

The compiler/linker will not generate this intentionally. The illegal opcode trap occurs when the opcode is undefined to the architecture. Some people will define all unused Flash with an illegal opcode such that if the program counter executes from the unused flash you will get a trap.