**Bit 15 of the status register is the T flag, which specifies whether the MC68000 is in trace mode. After each instruction is executed in the trace mode, a trap is forced so that a debugging program can monitor the results of that instruction’s execution.
== Privilege Operating Modes ==
The Motorola Two distinct operating modes are available with the 68000 has processor. The two modes: Supervisor are called user mode, and Usersupervisor mode.
In User mode, certain powerful commands like STOP, RESET, and A flag in the status register changes are blockedwill determine which state the processor is in at any one time. Debugging commands Certain instructions (MOVE to/from USPe.g., STOP) are also limited to Supervisor cannot be executed while the 68000 is in user mode. The , and a privilege violation exception process will be initiated by the processor uses two stack pointers: Supervisor Stack Pointer (SSP) for system tasks and User Stack Pointer (USP) for normal programsif such an execution is attempted.
Switching from User When the processor is in user mode to Supervisor mode happens only through exceptions or interrupts, ensuring the user programs cannot gain higher privileges on their own. All exceptions, including system calls and errors, automatically trigger Supervisor mode, and all stack pointer (USP) will be used by stack related memory accesses are treated as Supervisor referencesoperations. If true hardware-enforced privilege levels are neededConversely, later members of the 68k family supervisor stack pointer (such as SSP) will be used when the 68030, 68040, or 68060) are better suited since they include a built-processor is in Memory Management Unit (MMU) with proper privilege separation, preventing User supervisor mode programs from modifying system memory. It also aids in virtual memory management and multitasking. This separation helps protect the system from user program errors and malicious activities. But even on 68000, the privilege modes prevent user programs from interfering with the interrupt system.
== Instruction Set ==