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

    Purpose:        Breakpoint trap - stop for debugging
    Format:         opcode
    Operation:      PSL<TP> = 0; {breakpoint fault}
    C. Codes:       N = 0, Z = 0, V = 0, C = 0
    Exceptions:     None
    Opcode:         03    BPT      Breakpoint fault
    Description:    This instruction is used, together with the T-bit,
                    to implement debugging facilities.