2010 Microchip Technology Inc. DS39576C-page 1
PIC18FXX2/XX8
1.0 DEVICE OVERVIEW
This document includes the programming specifica-
tions for the following devices:
•PIC18F242
•PIC18F248
•PIC18F252
•PIC18F258
•PIC18F442
•PIC18F448
•PIC18F452
•PIC18F458
2.0 PROGRAMMING OVERVIEW
OF THE PIC18FXX2/XX8
The PIC18FXX2/XX8 can be programmed using the
high voltage In-Circuit Serial Programming
TM
(ICSP
TM
)
method, or the low voltage ICSP method. Both of these
can be done with the device in the users’ system. The
low voltage ICSP method is slightly different than the
high voltage method, and these differences are noted
where applicable. This programming specification
applies to PIC18FXX2/XX8 devices in all package
types.
2.1 Hardware Requirements
In high voltage ICSP mode, the PIC18FXX2/XX8
requires two programmable power supplies: one for
V
DD and one for MCLR/VPP. Both supplies should have
a minimum resolution of 0.25V. Refer to Section 6.0 for
additional hardware parameters.
2.1.1 LOW VOLTAGE ICSP
PROGRAMMING
In low voltage ICSP mode, the PIC18FXX2/XX8 can be
programmed using a V
DD source in the operating
range. This only means that MCLR
/VPP does not have
to be brought to a different voltage, but can instead be
left at the normal operating voltage. Refer to
Section 6.0 for additional hardware parameters.
2.2 Pin Diagrams
The pin diagrams for the PIC18FXX2/XX8 family are
shown in Figure 2-1. The pin descriptions of these dia-
grams do not represent the complete functionality of
the device types. Users should refer to the appropriate
device data sheet for complete pin descriptions.
TABLE 2-1: PIN DESCRIPTIONS (DURING PROGRAMMING): PIC18FXX2/XX8
Pin Name
During Programming
Pin Name Pin Type Pin Description
MCLR
/VPP VPP P Programming Enable
V
DD VDD P Power Supply
Vss V
SS P Ground
RB5 PGM I Low Voltage ICSP™ Input when LVP
Configuration bit equals ‘1’
(1)
RB6 SCLK I Serial Clock
RB7 SDATA I/O Serial Data
Legend: I = Input, O = Output, P = Power
Note 1: See Section 5.3 for more detail.
Flash Microcontroller Programming Specification
