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PIC16LF1847 Datasheet, PDF (327/408 Pages) Microchip Technology – 18/20/28-Pin Flash Microcontrollers with nanoWatt XLP Technology | |||
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28.0 IN-CIRCUIT SERIAL
PROGRAMMING⢠(ICSPâ¢)
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 ICSPâ¢
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 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 âPIC16193X/PIC16LF193X Memory
Programming Specificationâ (DS41360A).
28.1 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 28-1 for example circuit.
FIGURE 28-1:
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%
Note:
The MPLAB® ICD 2 produces a VPP volt-
age greater than the maximum VPP spec-
ification of the PIC16F/LF1847.
ï£ 2011 Microchip Technology Inc.
Preliminary
PIC16(L)F1847
RJ11-6PIN
6
5
4
3
2
1
To Target Board
DS41453A-page 329
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