PIC24FJ256GA110_10 Datasheet, PDF (255/330 Pages) Microchip Technology – 64/80/100-Pin, 16-Bit, General Purpose Flash Microcontrollers with Peripheral Pin Select

PIC24FJ256GA110 FAMILY
25.5 JTAG Interface
PIC24FJ256GA110 family devices implement a JTAG
interface, which supports boundary scan device
testing.
25.6 In-Circuit Serial Programming
PIC24FJ256GA110 family microcontrollers can be seri-
ally programmed while in the end application circuit.
This is simply done with two lines for clock (PGECx)
and data (PGEDx), and three other lines for power,
ground and the programming voltage. This allows
customers to manufacture boards with unprogrammed
devices and then program the microcontroller just
before shipping the product. This also allows the most
recent firmware or a custom firmware to be
programmed.
25.7 In-Circuit Debugger
When MPLAB^® ICD 2 is selected as a debugger, the
in-circuit debugging functionality is enabled. This func-
tion allows simple debugging functions when used with
MPLAB IDE. Debugging functionality is controlled
through the PGECx (Emulation/Debug Clock) and
PGEDx (Emulation/Debug Data) pins.
To use the in-circuit debugger function of the device,
the design must implement ICSP connections to
MCLR, VDD, VSS and the PGECx/PGEDx pin pair des-
ignated by the ICS Configuration bits. In addition, when
the feature is enabled, some of the resources are not
available for general use. These resources include the
first 80 bytes of data RAM and two I/O pins.
 2010 Microchip Technology Inc.
DS39905E-page 255