HPlogo System Debug Reference Manual > Appendix C Emulated/Translated CM Code

Debugging Emulated CM Code

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E0201 Edition 4 ♥
E0300 Edition 3
E0692 Edition 3

Debugging emulated CM code is relatively straightforward. Since each CM instruction is fetched and emulated, it is necessary to know only where you wish to set a breakpoint.

For emulated CM code you can break at any instruction: 

  $ cmdebug > B PROC+%6
  $ cmdebug > B PROC+%10
  $ cmdebug > B PROC+%15
The debugger places a special BRKP instruction at the specified addresses. When an emulated breakpoint is encountered, the emulator traps it into Debug before the original instruction is emulated. The environment variable entry_mode is set to "cm", and the user enters CMDebug. 

         CM Object Code

         CM Instructions

         +-------------+
         | PROC+%0     |
         | PROC+%1     |
         | PROC+%2     |
         | PROC+%3     |
  P  >   | PROC+%4     |
         | PROC+%5     |
     [1] | PROC+%6     |   <- Breakpoints are set in the object code
         | PROC+%7     |      at the specified addresses
     [2] | PROC+%10    |
         | PROC+%11    |
         | PROC+%12    |
         | PROC+%13    |
         | PROC+%14    |
     [3] | PROC+%15    |
         | PROC+%16    |
         +-------------+



Appendix C Emulated/Translated CM Code

Object Code Translation