PIC16F819 Microchip Technology Inc., PIC16F819 Datasheet - Page 103

• Manufacturer Part Number: PIC16F819
• Description: 18/20-pin Enhanced Flash Microcontrollers With Nanowatt Technology
• Manufacturer: Microchip Technology Inc.

12.17 In-Circuit Serial Programming
PIC16F818/819 microcontrollers can be serially
programmed while in the end application circuit. This is
simply done with two lines for clock and data and three
other lines for power, ground and the programming
voltage (see Figure 12-10 for an example). This allows
customers to manufacture boards with unprogrammed
devices and then program the microcontroller just
before shipping the product. This also allows the most
recent firmware or a custom firmware to be
programmed.
For more information on serial programming, please refer
to the “PIC16F818/819 Flash Memory Programming
Specification” (DS39603).
 2004 Microchip Technology Inc.
Note:
The Timer1 oscillator shares the T1OSI
and T1OSO pins with the PGD and PGC
pins
debugging.
When using the Timer1 oscillator, In-Circuit
Serial Programming™ (ICSP™) may not
function correctly (high voltage or low
voltage) or the In-Circuit Debugger (ICD)
may not communicate with the controller.
As a result of using either ICSP or ICD, the
Timer1 crystal may be damaged.
If ICSP or ICD operations are required, the
crystal should be disconnected from the
circuit (disconnect either lead) or installed
after programming. The oscillator loading
capacitors may remain in-circuit during
ICSP or ICD operation.
used
for
programming
and
FIGURE 12-10:
* Isolation devices (as required).
†
RB3/PGM
RB3 only used in LVP mode.
External
Connector
Signals
Data I/O
CLK
+5V
V
0V
PP
PIC16F818/819
*
To Normal
Connections
To Normal
Connections
TYPICAL IN-CIRCUIT
SERIAL PROGRAMMING
CONNECTION
*
*
*
DS39598E-page 101
PIC16F818/819
V
V
MCLR/V
RB6
RB7
RB3
DD
SS
†
V
DD
PP