25.9 Special ICPORT Features
(Designated Packages Only)
Under specific circumstances, the No Connect (NC)
pins of PIC18F4455/4550 devices in 44-pin TQFP
packages can provide additional functionality. These
features are controlled by device Configuration bits and
are available only in this package type and pin count.
25.9.1 DEDICATED ICD/ICSP PORT
The 44-pin TQFP devices can use NC pins to provide
an alternate port for In-Circuit Debugging (ICD) and
In-Circuit Serial Programming (ICSP). These pins are
collectively known as the dedicated ICSP/ICD port,
since they are not shared with any other function of the
device.
When implemented, the dedicated port activates three
NC pins to provide an alternate device Reset, data and
clock ports. None of these ports overlap with standard
I/O pins, making the I/O pins available to the user’s
application.
The dedicated ICSP/ICD port is enabled by setting the
ICPRT Configuration bit. The port functions the same
way as the legacy ICSP/ICD port on RB6/RB7.
Table 25-5 identifies the functionally equivalent pins for
ICSP and ICD purposes.
TABLE 25-5: EQUIVALENT PINS FOR
LEGACY AND DEDICATED
ICD/ICSP™ PORTS