VMS Help MACRO, VAX MACRO Assembler, Instructions, HALT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Purpose:        Stop processor operation
    Format:         opcode
    Operation:      If PSL<current_mode> NEQU kernel then
                      {reserved to Digital opcode fault}
                     else
                      {halt the processor}
    C. Codes:       N = 0, Z = 0, V = 0, C = 0 (fault)
                    Unaffected (processor halt)
    Exceptions:     Reserved to Digital opcode
    Opcode:         00    HALT     Halt
    Description:    If process is running in kernel mode, the processor
                    is halted. Otherwise, an opcode reserved to Digital
                    fault occurs. This opcode is 0 to trap many branches
                    to data.