Microchip Technology AC244045 Data Sheet

 2010-2012 Microchip Technology Inc.

DS41440C-page 329

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/V

PP

• V

DD

• V

SS

In Program/Verify mode the Program Memory, User IDs
and the Configuration Words are programmed through
serial communications. The ICSPDAT pin is a bidirec-
tional I/O used for transferring the serial data and the
ICSPCLK pin is the clock input. For more information on
ICSP™ refer to the “PIC16F/LF182X/PIC12F/LF1822
Memory Programming Specification

” (DS41403).

The device is placed into High-Voltage Programming
Entry mode by holding the ICSPCLK and ICSPDAT
pins low then raising the voltage on MCLR/V

PP

 to V

IHH

. 

Some programmers produce V

PP

 greater than V

IHH

(9.0V), an external circuit is required to limit the V

PP

voltage. See 

 for example circuit.

V

REF

V

PP

V

DD

V

SS

ICSP_DATA

ICSP_CLOCK

NC

RJ11-6PIN

RJ11-6PIN

R1

270 Ohm

To MPLAB

®

 ICD 2

To Target Board

1
2
3
4
5
6

1

2

3

4

5

6

R2

R3

10k 1%

24k 1%

LM431BCMX

A

2

3

6

7

8

A

A

A

K

NC

NC

1

4

5

The MPLAB ICD 2 produces a V

PP

voltage greater than the maximum V

PP

specification of the PIC16(L)F1825/1829.