Microchip Technology PICkit 3 Starter Kit DV164130 DV164130 Benutzerhandbuch
Produktcode
DV164130
PICkit™ 3 USER’S GUIDE
© 2009 Microchip Technology Inc.
DS51795A-page 37
Chapter 7. Frequently Asked Questions (FAQs)
7.1
INTRODUCTION
Look here for answers to frequently asked questions about the PICkit 3
programmer/debugger system.
programmer/debugger system.
7.2
HOW DOES IT WORK
• What's in the silicon that allows it to communicate with the PICkit 3
programmer/debugger?
PICkit 3 programmer/debugger can communicate with Flash silicon via the ICSP
interface. It uses the debug executive downloaded into program or test memory.
interface. It uses the debug executive downloaded into program or test memory.
• How is the throughput of the processor affected by having to run the debug
executive?
The debug executive doesn’t run while in Run mode, so there is no throughput
reduction when running your code, i.e., the debugger doesn’t ‘steal’ any cycles
from the target device.
reduction when running your code, i.e., the debugger doesn’t ‘steal’ any cycles
from the target device.
• How does the PICkit 3 programmer/debugger compare with other in-circuit
emulators/debuggers?
Please refer to Section 2.2 “PICkit 3 vs. PICkit 2”.
• On the MPLAB ICE 2000/4000 debuggers, the data must come out on the
bus in order to perform a complex trigger on that data. Is this also required
on the PICkit 3 programmer/debugger? For example, could I halt based on a
flag going high?
on the PICkit 3 programmer/debugger? For example, could I halt based on a
flag going high?
The MPLAB ICE 2000/4000 debuggers use a special debugger chip (-ME) for
monitoring. There is no -ME with the PICkit 3 programmer/debugger so there are
no busses to monitor externally. With the PICkit 3 programmer/debugger, rather
than using external breakpoints, the built-in breakpoint circuitry of the debug
engine is used – the busses and breakpoint logic are monitored inside the part.
monitoring. There is no -ME with the PICkit 3 programmer/debugger so there are
no busses to monitor externally. With the PICkit 3 programmer/debugger, rather
than using external breakpoints, the built-in breakpoint circuitry of the debug
engine is used – the busses and breakpoint logic are monitored inside the part.
• Does the PICkit 3 programmer/debugger have complex breakpoints like
MPLAB ICE 2000/4000?
No. But you can break based on a value in a data memory location or program
address. See Section 9.3.1 “Breakpoints Dialog” for more information.
address. See Section 9.3.1 “Breakpoints Dialog” for more information.
• Is the PICkit 3 optoisolated or electrically isolated?
No. You cannot apply a floating or high voltage (120V) to the current system.
• What limitations are there with the standard cable?
The standard ICSP RJ-11 cable does not allow for clock speeds greater than
about 15 Mbps.
about 15 Mbps.