PIC16F/LF1946/47
27.0 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
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 ICSPCLK pin is the clock input. For more
information
on
ICSP™
refer
to
the
“PIC16F193X/LF193X/PIC16F194X/LF194X Memory
Programming Specification” (DS41397).
27.1 High-Voltage Programming Entry
Mode
The device is placed into High-Voltage Programming
Entry mode by holding the ICSPCLK and ICSPDAT
pins low then raising the voltage on MCLR/VPP to VIHH.
Some programmers produce VPP greater than VIHH
(9.0V), an external circuit is required to limit the VPP
voltage. See Figure 27-1 for example circuit.
FIGURE 27-1:
VPP LIMITER EXAMPLE CIRCUIT
RJ11-6PIN
6
5
4
3
2
1
VPP
2
VDD
3
VSS
4
ICSP_DATA
ICSP_CLOCK
NC
5
6
1
RJ11-6PIN
R1
To MPLAB® ICD 2
To Target Board
270 Ohm
LM431BCMX
1
2
A
A
A
A
K
U1
3
6
7
4
5
NC
NC
VREF
8
R2
R3
10k 1%
24k 1%
2010 Microchip Technology Inc.
Preliminary
DS41414A-page 363
MICROCHIP [ MICROCHIP ]
