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12.1.9 Restriction of LPT port
1. The emulator uses a printer (parallel) port during LPT communications with personal computer.
The IAR C compiler also uses this printer (parallel) port.
When using the personal computer and the emulator during LPT communications, a problem
arises that you cannot compile a program using the IAR C compiler.
If this happens, you must take either of the countermeasures listed below:
- Connect the personal computer to the emulator in any mode other than the ECP mode.
- Start compiling the program after the debugger is terminated.
2. When you debug programs using the LPT parallel interface on the host PC running Windows XP,
the following symptoms may appear:
- The debugger becomes frozen.
- The debugger's operation gets extraordinarily slower.
- Communication errors arise and the emulator debugger stops operating.
- Various types of errors other than communication errors also take place successively. In this
case, the emulator debugger continues operating however.
The cause of this problem is that if the debugger is invoked while the standard driver Parport.sys of
Windows XP is communicating with the LPT port, the debugger is unable to communicate with the
emulator. Then, this problem can be circumvented in either of the following methods; however, you
need to take no measures if you have not experienced it in your PC under the above-mentioned
conditions:
- Execute the utility program to fix (LptFix.exe).
LptFix.exe disables the Parport.sys driver. Then, if any device other than the emulator is
connected to the LPT port after LptFix.exe is executed, the device may not operate properly. In
such a case you are encouraged to adopt method shown below.
- If you launch the emulator for the first time after starting the PC, invoke the debugger one or
more minutes after the emulator starts operating. Otherwise, you can invoke the debugger
immediately after the emulator has started.
Here is the usage of LptFix.exe:
1. Invoke the command prompt and move to the folder where the LptFix.exe file resides.
2. Enter the following command on the command line:
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>LptFix
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3. Restart the PC.
If LptFix.exe is executed, be sure to make it ineffective to enable the Parport.sys driver as explained
below, every time after ending debugging operations and disconnecting the emulator. To make
LptFix.exe ineffective to enable Parport.sys, execute following command line:
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>LptFix /U
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