PIC18F97J60 Datasheet, PDF (360/474 Pages) Microchip Technology – 64/80/100-Pin, High-Performance, 1 Mbit Flash Microcontrollers with Ethernet

PIC18F97J60 FAMILY
24.6 Program Verification and
Code Protection
For all devices in the PIC18F97J60 family, the on-chip
program memory space is treated as a single block.
Code protection for this block is controlled by one
Configuration bit, CP0. This bit inhibits external reads
and writes to the program memory space. It has no
direct effect in normal execution mode.
24.6.1 CONFIGURATION REGISTER
PROTECTION
The Configuration registers are protected against
untoward changes or reads in two ways. The primary
protection is the write-once feature of the Configuration
bits which prevents reconfiguration once the bit has
been programmed during a power cycle. To safeguard
against unpredictable events, Configuration bit
changes resulting from individual cell level disruptions
(such as ESD events) will cause a parity error and
trigger a device Reset.
The data for the Configuration registers is derived from
the Flash Configuration Words in program memory.
When the CP0 bit set, the source data for device
configuration is also protected as a consequence.
24.7 In-Circuit Serial Programming
PIC18F97J60 family 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. 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.
24.8 In-Circuit Debugger
When the DEBUG Configuration bit is programmed to
a ‘0’, the In-Circuit Debugger functionality is enabled.
This function allows simple debugging functions when
used with MPLAB^® IDE. When the microcontroller has
this feature enabled, some resources are not available
for general use. Table 24-3 shows which resources are
required by the background debugger.
TABLE 24-3: DEBUGGER RESOURCES
I/O pins:
RB6, RB7
Stack:
2 levels
Program Memory:
512 bytes
Data Memory:
10 bytes
DS39762A-page 358
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© 2006 Microchip Technology Inc.