Debugging of a Program Process

YASH PAL,

The process of debugging a program is similar to troubleshooting hardware, but it is much more difficult and cumbersome; some clues give an alert to the programmer to know about errors made by them. Either the program works or does not, the position at which it has exactly gone wrong can be known by using program debugging.

The debugging process can be divided into two parts:

  1. Static Debugging
  2. Dynamic Debugging

Static Debugging

Static debugging is similar to visual inspection of hardware by a paper-and-pencil check of the flowchart and machine code. As stated already, these errors can be known by some clues. These clues are those situations that must be checked carefully because they are some common errors, which are:

  1. Selecting the wrong machine code.
  2. Specifying the wrong group instruction.
  3. Giving the wrong order of high-order and low-order bytes.
  4. Failure to set a flag before using the jump instruction.
  5. Failure in indexing and counting.
  6. Failure to clear the accumulator when it is used in an arithmetic operation.
  7. Failure to clear the register when it is used to track some data, like carry.

These errors must be corrected before entering the machine code in the R/W memory of the system.

Dynamic Debugging

Sometimes, even after static debugging, the program does not work, so the user can go for dynamic debugging. The tools of dynamic debugging are:

  1. Single step
  2. Break point

Single step – Single step key on the keyboard of a single-board microcomputer allows to execute one instruction at a time, and after than programmer can check for the expected result by examining the memory or register and continue. It is advised to the programmers to troubleshoot the programs for lesser number of count then it is required.

Break point – Break point facility, provided is a software service routine that allows the programmer to execute a program in sections. Breakpoints are inserted in the program by writing (inserting) RST instructions, and as the execution key is pushed, execution takes place up to the first breakpoint, and after that, the user can check for the expected result and then go to the next breakpoint and soon.

engineering subjects Microprocessor