Inspect Manual

High-Level Inspect Commands
Inspect Manual—429164-006
6-25
BREAK

Write Availability
Write breakpoints are available on all TNS processors, but not on NSR-L
processors. When a high-level write breakpoint is reported (TNS systems only) and
the value of the variable has not changed, Inspect issues this warning:

Machine Dependency
The program location after a data breakpoint is triggered is machine-dependent.
On TNS systems, it might differ by an instruction. On TNS/R systems, it might differ
by more than an instruction. For more information, see Section 15, Using Inspect
on a TNS/R System.

Single-Byte Data Objects
A data breakpoint is associated with a single 16-bit word; therefore, if you set a
breakpoint on a data object that occupies a single byte, the breakpoint is
associated with the word that contains the data object. Subsequent access of
either byte of the word generates a break event for read and write breakpoints.

Multi-Word Data Objects
A data breakpoint is associated with a single 16-bit word; therefore, if you set a
breakpoint on a data object that occupies multiple words (a floating point value, or
character field in record or structure, for example), the breakpoint is associated
with the first word of the data object. If your program accesses one of the other
words of the data object without affecting the first word, a break event does not
occur.

Byte Data starting on an Odd Byte
A field in a record or structure might start on an odd byte boundary. Setting a write
or read/write data breakpoint for the field might result in unrelated breakpoints
being reported when the trailing byte of the previous field is accessed.

Initialization
Data breakpoints should be set after initialization has taken place. Variable
locations might not be established in memory until initialization is complete.

Local and Sublocal Data Objects
A data breakpoint set on a local or a sublocal variable persists even after its
containing scope unit has completed execution. It persists because it is associated
with a given physical address. Consequently, if a scope unit later allocates a local
or sublocal variable at the same physical address, that new variable has the old
data breakpoint associated with it.
** Inspect warning 364 ** Value of variable did not change;
breakpoint may have been triggered by an access
to the containing 16-bit word