3.3.5.2 ICSP Target Connection Circuitry

The figure below shows the interconnections of the MPLAB ICE 4 In-Circuit Emulator to the connector on the target board. The diagram also shows the wiring from the connector to a device on the target PCB. A pull-up resistor Rpu, usually around 10 kΩ, connected from the VPP/MCLR line to the VDD is recommended so that the line may be strobed low to reset the device.

Figure 3-27. ICSP Connection Target Circuitry
Table 3-11. Target Connector and Related Device I/O
Pin No.Device I/ODescription
1Vpp/MCLRThe emulator requires access to Vpp for programming and debugging the device.
2VddTarget Vdd is sensed by the emulator to allow level translation for target low-voltage operation and to detect a device. If the emulator does not sense voltage on its Vdd line, it will not connect with the device.
3VssTarget Vss is sensed by the emulator.
Note: The emulator DOES NOT provide target Vss or ground.
4PGDThe emulator requires access to PGD and PGC for programming and debugging the device.
5PGC
Table 3-12. Circuitry on Device I/O
Device I/ODescription
Vpp/nMCLR and VddA pull-up resistor (10kΩ typical) should be connected from the Vpp/MCLR line to Vdd so that the line may be strobed low to reset the device.
XTALThe target device must be running with an oscillator for the emulator to function as a debugger.
AVdd, AVssNot all devices have the AVdd and AVss lines, but if they are present on the target device, all must be connected to the appropriate levels in order for the emulator to operate. This also applies to voltage regulator pins (e.g., ENVREG/DISVREG on PIC24FJ MCUs).
Vdd, Vss, AVdd, AVssIn general, it is recommended per device data sheet that all Vdd/AVdd and Vss/AVss lines be connected to the appropriate levels. For devices with a Vcap pin (e.g., PIC18FXXJ devices), the appropriately-valued capacitor should be placed as close to the Vcap pin as possible.