Microchip Technology MPLAB ICE, User Manual

Page: 139 / 192

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2001 Microchip Technology Inc. DS51159B-page 139
Troubleshooting
If you must change the characteristics of the parallel port and other devices
have previously been defined on that port, you should follow the instructions
for that device first, deleting that device and associated drivers from the
system. Then reconfigure the port and reinstall the device. This will ensure
that the alternate device will pick up the new port characteristics.
8.4.8 Speed Issues
Using MPLAB ICE in compatible (nibble) mode will result in decreased
performance when communicating with the emulator. This is most noticeable
during upload and download of large amounts of data, but does not affect the
real time performance of the system.
Once determining that a compatible mode works, it may be worth trying other
parallel port modes (i.e., bi-directional) to improve performance.
8.4.9 Nothing I Do Works
It is possible that none of the settings of the parallel port will work properly
with MPLAB ICE. This is true even though other parallel port devices (e.g.,
printers) may function properly on the port. This is not a malfunction of
MPLAB ICE. MPLAB ICE depends on a standard IEEE implementation, while
printers may depend on the operating system to interface with the parallel
port.
In this case, a separate, dedicated parallel interface card is the recommended
solution. Follow the manufacturer’s instructions for inserting the card into the
PC and making it available to the operating system. Most such devices will
use a standard implementation and are very likely to be compatible with
MPLAB ICE.