
                         SET BREAKPOINT function

	The SET BREAKPOINT function is used to enable one of the four
hardware breakpoint used by the development system.

	Upon invocation, the SET BREAKPOINT function requests an
address at which to set a breakpoint. You may supply a hex-decimal
number or default the entry. In either case, you are next asked to
supply a mask for the breakpoint comparison. You may, again, supply
a hex-decimal number or default the entry. If you default both
requests by pressing <Enter> to each, the SET BREAKPOINT function
prints a list of the currently active breakpoint. If you supply a
valid hex-decimal number to both requests, the breakpoint will be
accepted. The breakpoint address and mask value are first written
to the BCCDI board then entered into a table of active breakpoint
maintained by this monitor program. Finally, the table of
breakpoint is printed to show you that the breakpoint has been
accepted. You may now return to the MAIN menu.

                     ADDITIONAL INFORMATION.

	The BCCDI board includes a 32 bit breakpoint comparator chip
labeled U1. This chip contains four 32 bit address comparator
circuits. Each address comparator circuit has the ability to
separately enable or disable the comparison of any of the twenty
four bit address bus signals and four bits of bus control
information. The mask value is used for this bit by bit enable
function. During the initialization stage of this monitor, the
monitor writes the hex-decimal value $007FFFFE to all four mask
registers and $00000000 to all address registers of U1.

%END
