The 68020 and 68030 CPUs were desig

The 68020 and 68030 CPUs were designed with the separate 68881 chip in mind. Their instruction sets reserved the "F-line" instructions - that is, all opcodes beginning with the hexadecimal digit "F" were "traps" which would throw an interrupt, handing control to the computer's operating system. If a 68881 were present in the system, the CPU would allow it to execute the instruction. If not, the OS would either call an FPU emulator to execute the instruction using 68020 integer-based software code, or would return an error code to the program.