2.4 ICSP Pins

The PGCx and PGDx pins are used for ICSP and debugging purposes. It is recommended to keep the trace length between the ICSP connector and the ICSP pins on the device as short as possible. If the ICSP connector is expected to experience an ESD event, a series resistor is recommended, with the value in the range of a few tens of Ohms, not to exceed 100 Ohms.

Pull-up resistors, series diodes and capacitors on the PGCx and PGDx pins are not recommended as they will interfere with the programmer/debugger communications to the device. If such discrete components are an application requirement, they should be removed from the circuit during programming and debugging. Alternatively, refer to the AC/DC characteristics and timing requirements information in the respective device Flash programming specification for information on capacitive loading limits and pin Voltage Input High (VIH) and Voltage Input Low (VIL) requirements.

Ensure that the “Communication Channel Select” (i.e., PGCx/PGDx pins) programmed into the device matches the physical connections for the ICSP to PICkit™ 3, MPLAB® ICD 3 or MPLAB REAL ICE™ emulator.

For more information on MPLAB ICD 2, MPLAB ICD 3 and REAL ICE emulator connection requirements, refer to the following documents that are available on the Microchip website.

  • “Using MPLAB® ICD 3 In-Circuit Debugger” (poster) (DS51765)
  • “Development Tools Design Advisory” (DS51764)
  • “MPLAB® REAL ICE™ In-Circuit Emulator User’s Guide for MPLAB X IDE” (DS50002085)
  • “Using MPLAB® REAL ICE™ In-Circuit Emulator” (poster) (DS51749)