conditional breakpoints

2 files changed, 49 insertions, 5 deletions

diff --git a/doc/mdk_gstart.texi b/doc/mdk_gstart.texi
index 4c8b025..25764a0 100644
--- a/doc/mdk_gstart.texi
+++ b/doc/mdk_gstart.texi
@@ -423,7 +423,11 @@ thus, in the above example we have requested a breakpoint at a line
 which does not correspond to a MIX instruction and the breakpoint is set
 at the first line containing a real instruction after the given one. To
 unset breakpoints, use @code{cbpa ADDRESS} and @code{cbp LINE_NO}, or
-@code{cabp} to remove all currently set breakpoints. 
+@code{cabp} to remove all currently set breakpoints. You can also set
+conditional breakpoints, i.e., tell @code{mixvm} to interrupt program
+execution whenever a register, a memory cell, the comparison flag or the
+overflow toggle change using the commands @w{@code{sbp[rmco]}}
+(@pxref{Debug commands}).
 
 MIXAL lets you define symbolic constants, either using the @code{EQU}
 pseudoinstruction or starting an instruction line with a label (which
diff --git a/doc/mdk_mixvm.texi b/doc/mdk_mixvm.texi
index 87449b1..f5538cd 100644
--- a/doc/mdk_mixvm.texi
+++ b/doc/mdk_mixvm.texi
@@ -220,6 +220,7 @@ execution).
 @end deffn
 
 @deffn {debug command} sbp line_number
+@deffnx {debug command} cbp line_no
 Sets a breakpoint at the specified source file line number. If the line
 specified corresponds to a command or to a MIXAL pseudoinstruction which
 does not produce a MIX instruction in the binary file (such as
@@ -252,22 +253,61 @@ since line 7 is the first one compiled into a MIX instruction (at
 address 3000). In order to @code{sbp} to work, the source file must be
 compiled using the @code{-g} flags, which tells @code{mixasm} to include
 debug information in the binary @file{.mix} file.
+
+The command @code{cbp} clears a (previously set) breakpoint at the given
+source file line.
 @end deffn
 
 @deffn {debug command} spba address
+@deffnx {debug command} cbpa address
 Sets a breakpoint at the given memory @var{address}. The argument must
 be a valid MIX memory address, i.e., it must belong into the range
 @w{[0-3999]}. Note that no check is performed to verify that the
 specified address is reachable during program execution. No debug
 information is needed to set a breakpoint by address with @code{sbpa}.
+The command @code{cbpa} clears a (previously set) breakpoint at the
+given memory address.
+@end deffn
+
+@deffn {debug command} sbpr A | X | J | Ii
+@deffnx {debug command} cbpr A | X | J | Ii
+Sets a conditional breakpoint on the specified register change. For
+instance, 
+
+@example
+sbpr I1
+@end example
+
+@noindent
+will cause an interruption during program execution whenever the
+contents or register @code{I1} changes. A previously set breakpoint is
+cleared using the @code{cbpr} command.
+@end deffn
+
+@deffn {debug command} sbpm address
+@deffnx {debug command} cbpm address
+Sets a conditional breakpoint on the specified memory cell change. The
+argument must be a valid MIX memory address, i.e., it must belong into
+the range @w{[0-3999]}. For instance,
+
+@example
+sbpm 1000
+@end example
+
+@noindent
+will cause an interruption during program execution whenever the
+contents or of the memory cell number 1000 changes. A previously set
+breakpoint is cleared using the @code{cbpm} command.
 @end deffn
 
-@deffn {debug command} cbp line_no
-Clears a (previously set) breakpoint at the given source file line.
+@deffn {debug command} sbpo 
+@deffnx {debug command} cbpo 
+Sets/clears a conditional breakpoint on overflow toggle change.
 @end deffn
 
-@deffn {debug command} cbpa address
-Clears a (previously set) breakpoint at the given memory address.
+@deffn {debug command} sbpc 
+@deffnx {debug command} cbpc 
+Sets/clears a conditional breakpoint on comparison flag change.
 @end deffn
 
 @deffn {debug command} cabp