Microchip Technology MPLAB ICD 5 User Manual

Operaon
User Guide
© 2023 Microchip Technology Inc. and its subsidiaries
DS-50003529B - 36
mode must be used. The software front-end handles this automatically provided that the necessary
SPI pins are connected. It can also be set manually using SPI programming in the software front-end.
Either: Attempt to start a debug session on the debugWIRE part. If the debugWIRE interface is not enabled, the software
front-end will oer to retry or attempt to enable debugWIRE using SPI programming. If you have the full SPI header
connected, debugWIRE will be enabled and you will be asked to toggle power on the target. This is required for the
fuse changes to be eective.
Or: Open the programming dialog in Microchip Studio in SPI mode and verify that the signature matches the correct
device. Check the DWEN fuse to enable debugWIRE.
Important:
Make sure to leave the SPIEN fuse programmed and the RSTDISBL fuse unprogrammed!
Not doing this will render the device stuck in debugWIRE mode and High-Voltage
programming will be required to revert the DWEN setting.
To disable the debugWIRE interface, use High-Voltage programming to unprogram the DWEN fuse.
Alternately, use the debugWIRE interface itself to temporarily disable itself, which will allow SPI
programming to take place, provided that the SPIEN fuse is set.
Important:
If the SPIEN fuse was NOT left programmed, the software front-end will not be able to
complete this operation and High-Voltage programming must be used.
In MPLAB X IDE, if debugWIRE is enabled on the target device and an SPI programming session
is attempted, the IDE will oer to disable debugWIRE rst. In Microchip Studio, this must be done
manually during a debug session, by selecting the Disable debugWIRE and Close option from the
Debug menu. The debugWIRE interface will be temporarily disabled and the software front-end will
use SPI programming to unprogram the DWEN fuse.
Having the DWEN fuse programmed enables some parts of the clock system to be running in all
sleep modes. This will increase the power consumption of the AVR while in sleep modes. The DWEN
Fuse should, therefore, always be disabled when debugWIRE is not used.
When designing a target application PCB where debugWIRE will be used, the following
considerations must be made for correct operation:
• Pull-up resistors on the dW/(RESET) line must not be smaller than 10 kΩ. The pull-up resistor is
not required for debugWIRE functionality since the debugger tool provides this.
• Any stabilizing capacitor connected to the RESET pin must be disconnected when using
debugWIRE since they will interfere with correct operation of the interface.
• All external Reset sources or other active drivers on the RESET line must be disconnected, since
they may interfere with the correct operation of the interface.
Never program the lock-bits on the target device. The debugWIRE interface requires that lock-bits
are cleared to function correctly.
4.3.1.5.2 debugWIRE Soware Breakpoints
The debugWIRE OCD is drastically downscaled when compared to the megaAVR (JTAG) OCD. This
means that it does not have any Program Counter breakpoint comparators available to the user
for debugging purposes. One such comparator does exist for purposes of run-to-cursor and single-
stepping operations, but additional user breakpoints are not supported in hardware.
Instead, the debugger must make use of the AVR BREAK instruction. This instruction can be placed
in FLASH, and when loaded for execution, it will cause the AVR CPU to enter Stopped mode. To

Microchip Technology MPLAB ICD 5 Specifications

General

Brand	Microchip Technology
Model	MPLAB ICD 5
Category	Microcontrollers
Language	English