
2010-2012 Microchip Technology Inc.
DS41417B-page 183
PIC16(L)F722A/723A
20.0 IN-CIRCUIT SERIAL
PROGRAMMING (ICSP)
ICSP programming allows customers to manufacture
circuit boards with unprogrammed devices. Programming
can be done after the assembly process allowing the
device to be programmed with the most recent firmware
or a custom firmware. Five pins are needed for ICSP
programming:
ICSPCLK
ICSPDAT
MCLR/VPP
VDD
VSS
The device is placed into Program/Verify mode by
holding the ICSPCLK and ICSPDAT pins low then
raising the voltage on MCLR/VPP from 0v to VPP. In
Program/Verify mode the Program Memory, User IDs
and the Configuration Words are programmed through
serial communications. The ICSPDAT pin is a
bidirectional I/O used for transferring the serial data and
the ISCPCLK pin is the clock input. For more information
on ICSP refer to the “PIC16F72X/PIC16LF72X
Programming Specification” (DS41332).
FIGURE 20-1:
TYPICAL CONNECTION FOR ICSP PROGRAMMING
Note:
The ICD 2 produces a VPP voltage greater
than the maximum VPP specification of the
PIC16(L)F722A/723A. When using this
programmer, an external circuit, such as
the AC164112 MPLAB ICD 2 VPP voltage
limiter, is required to keep the VPP voltage
within the device specifications.
VDD
VPP
GND
External
Device to be
Data
Clock
VDD
MCLR/VPP
VSS
ICSPDAT
ICSPCLK
*
To Normal Connections
* Isolation devices (as required).
10k
Programming
Signals
Programmed
VDD