PIC16F1847_13 Datasheet, PDF (327/440 Pages) Microchip Technology – 18/20/28-Pin Flash Microcontrollers with XLP Technology

28.0 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 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 “PIC16193X/PIC16LF193X Memory
Programming Specification” (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.
PIC16(L)F1847
28.2 Low-Voltage Programming Entry
Mode
The Low-Voltage Programming Entry mode allows the
PIC^® Flash MCUs devices to be programmed using
VDD only, without high voltage. When the LVP bit of
Configuration Words is set to ‘1’, the low-voltage ICSP
programming entry is enabled. To disable the
Low-Voltage ICSP mode, the LVP bit must be
programmed to ‘0’.
Entry into the Low-Voltage Programming Entry mode
requires the following steps:
1. MCLR is brought to VIL.
2. A 32-bit key sequence is presented on
ICSPDAT, while clocking ICSPCLK.
Once the key sequence is complete, MCLR must be
held at VIL for as long as Program/Verify mode is to be
maintained.
If low-voltage programming is enabled (LVP = 1), the
MCLR Reset function is automatically enabled and
cannot be disabled. See Section 7.4 “MCLR” for more
information.
The LVP bit can only be reprogrammed to ‘0’ by using
the High-Voltage Programming mode.
28.3 Common Programming Interfaces
Connection to a target device is typically done through
an ICSP™ header. A commonly found connector on
development tools is the RJ-11 in the 6P6C (6-pin, 6
connector) configuration. See Figure 28-1.
FIGURE 28-1:
ICD RJ-11 STYLE
CONNECTOR INTERFACE
ICSPDAT
VDD
2 4 6 NC
ICSPCLK
13 5
Target
VPP/MCLR
VSS
PC Board
Bottom Side
Pin Description*
1 = VPP/MCLR
2 = VDD Target
3 = VSS (ground)
4 = ICSPDAT
5 = ICSPCLK
6 = No Connect
 2011-2013 Microchip Technology Inc.
Preliminary
DS40001453D-page 327