PIC16LF1904 Datasheet, PDF (219/288 Pages) Microchip Technology – 28/40/44-Pin Flash-Based, 8-Bit CMOS Microcontrollers with LCD Driver and nanoWatt XLP Technology

PIC16LF1904/6/7
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
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/PIC16LF
190X Memory
(DS41397).
Programming
Specification”
20.1 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 20-1 for example circuit.
FIGURE 20-1:
VPP LIMITER EXAMPLE CIRCUIT
VPP
VDD
VSS
ICSP_DATA
ICSP_CLOCK
NC
1
2
3
4
5
6
RJ11-6PIN
To MPLAB^® ICD 2
R1
270 Ohm
LM431BCMX
2
3
6
7
A
A
A
A
U1 ^{K 1}
NC
NC
4
5
VREF
8
R2
R3
10k 1% 24k 1%
RJ11-6PIN
6
5
4
3
2
1
To Target Board
Note:
The MPLAB^® ICD 2 produces a VPP
voltage greater than the maximum VPP
specification of the PIC16LF1904/6/7.
 2011 Microchip Technology Inc.
Preliminary
DS41569A-page 219