PIC16LF720_11 Datasheet, PDF (171/244 Pages) Microchip Technology – 20-Pin Flash Microcontrollers with nanoWatt XLP Technology

PIC16(L)F720/721
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).
Note:
The MPLAB^® ICD 2 produces a VPP volt-
age greater than the maximum VPP spec-
ification of the PIC16(L)F720/721. 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.
FIGURE 20-1:
TYPICAL CONNECTION FOR ICSP™ PROGRAMMING
External
Programming
Signals
VDD
VPP
GND
Data
Clock
VDD
10k
Device to be
Programmed
VDD
MCLR/VPP
VSS
ICSPDAT
ICSPCLK
*
*
*
To Normal Connections
* ^{Isolation devices (as required).}
 2011 Microchip Technology Inc.
Preliminary
DS41430B-page 171