NAME	BKPT -- Break-point
SYNOPSIS	BKPT #<data>
FUNCTION	This instruction is used to support the program breakpoint function for debug monitors and real-time hardware emulators, and the operation will be dependent on the implementation. Execution of this instruction will cause the MC68010 to run a breakpoint acknowledge bus cycle and zeros on all address lines, but an MC68020 will place the immediate data on lines A2, A3, and A4, and zeros on lines A0 and A1. Whether the breakpoint acknowledge cycle is terminaled with (DTACK), (BERR), or (VPA) the processor always takes an illegal instruction exception. During exception processing, a debug monitor can distinguish eight different software breakpoints by decoding the field in the BKPT instruction. For the MC68000 and the MC68HC000, this instruction causes an illegal instruction exception, but does not run the breakpoint acknowledge bus cycle. There are two possible responses on an MC68020: normal and exception. The normal response is an operation word (typically the instruction the BKPT originally replaced) on the data lines with the (DSACKx) signal asserted. The operation word is the executed in place of the breakpoint instruction. For the exception response, a bus error signal will cause the MC68020 to take an illegal instruction exception, just as an MC68010 or MC68000 would do.
FORMAT	15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 1 0 0 1 0 0 0 0 1 0 0 1 No BREAKPT. Number of break-point: Value between 0 and 7.
RESULT	None.

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