PIC12F1840 MICROCHIP [Microchip Technology], PIC12F1840 Datasheet - Page 301

• Manufacturer Part Number: PIC12F1840
• Description: 8-Pin Flash Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

28.0
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
• V
• V
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/LF1847/PIC12F/LF1840
Memory Programming Specification”, (DS41439).
28.1
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
Some programmers produce V
(9.0V), an external circuit is required to limit the V
voltage. See
FIGURE 28-1:
 2011 Microchip Technology Inc.
Note:
DD
SS
IN-CIRCUIT SERIAL
PROGRAMMING™ (ICSP™)
High-Voltage Programming Entry
Mode
PP
The MPLAB ICD 2 produces a V
voltage greater than the maximum V
specification of the PIC12F/LF1840.
Figure 28-1
To MPLAB
ICSP_CLOCK
RJ11-6PIN
ICSP_DATA
VPP LIMITER EXAMPLE CIRCUIT
V
V
V
for example circuit.
®
NC
PP
DD
SS
ICD 2
1
2
3
4
5
6
PP
greater than V
PP
270 Ohm
to V
R1
10k 1%
IHH
Preliminary
2
3
6
7
PP
PP
R2
IHH
PP
LM431BCMX
.
A
A
A
A
V
U1
REF
8
NC
NC
24k 1%
K
R3
1
4
5
PIC12F/LF1840
To Target Board
6
5
4
3
2
1
RJ11-6PIN
DS41441A-page 301