Notes And Tips; Entering Debug Session With Codewarrior; Reading Peripheral Status; Breakpoints And Bgnd Instruction - SofTec Microsystems PK-HCS12E128 User Manual

4. Debugging Features
Note: the Single Step command (in a C source code) and the Step Over and Step Out
commands (both in a C and Assembly source code) use one hardware breakpoint.

Notes and Tips

Entering Debug Session with CodeWarrior

When entering a debug session, the target microcontroller's FLASH memory is
automatically erased, unsecured and programmed with the user application.
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Note: when programming the microcontroller with the user application (after having
unsecured the device), CodeWarrior ignores (doesn't program) the security bits. As a result,
when entering a debug session, the device is always unsecured, regardless of other user
settings.

Reading Peripheral Status

Care must be taken when reading some peripheral's status/data registers, since a reading
operation may cause the clearing of flags. This may happen when the Memory window or
the Data window is open, since these windows read microcontroller's resources during
refresh operations.

Breakpoints and BGND Instruction

The BGND Assembly instruction forces the target microcontroller to enter the Active
Background Debug mode, stopping program execution. CodeWarrior recognizes this event
as a breakpoint and updates the contents of registers, memory, etc. Successive commands
(Start/Continue, Single Step, etc.) will continue the execution of the program from the next
instruction.
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