PIC16F5X
8.0
SPECIAL FEATURES OF THE
CPU
The Sleep mode is designed to offer a very low-current
Power-down mode. The user can wake-up from Sleep
through external Reset or through a Watchdog Timer
time-out. Several oscillator options are also made
available to allow the part to fit the application. The RC
oscillator option saves system cost, while the LP crystal
option saves power. A set of Configuration bits are
used to select various options.
What sets a microcontroller apart from other proces-
sors are special circuits that deal with the needs of real-
time applications. The PIC16F5X family of microcon-
trollers have a host of such features intended to
maximize system reliability, minimize cost through
elimination of external components, provide power-
saving operating modes and offer code protection.
These features are:
•
•
•
•
•
•
•
•
•
Oscillator Selection
Reset
Power-on Reset
Device Reset Timer
Watchdog Timer (WDT)
Sleep
Code protection
User ID locations
In-Circuit Serial Programming™ (ICSP™)
8.1
Configuration Bits
Configuration bits can be programmed to select various
device configurations. Two bits are for the selection of
the oscillator type; one bit is the Watchdog Timer
enable bit; one bit is for code protection for the
PIC16F5X devices (Register 8-1).
The PIC16F5X family has a Watchdog Timer which can
be shut off only through Configuration bit WDTE. It runs
off of its own RC oscillator for added reliability. There is
an 18 ms delay provided by the Device Reset Timer
(DRT), intended to keep the chip in Reset until the
crystal oscillator is stable. With this timer on-chip, most
applications need no external Reset circuitry.
REGISTER 8-1:
—
bit 11
—
CONFIGURATION WORD FOR PIC16F5X
—
—
—
—
—
—
CP
WDTE
FOSC1
FOSC0
bit 0
bit 11-4:
Unimplemented:
Read as ‘1’
bit 3:
CP:
Code Protection bit.
1
= Code protection off
0
= Code protection on
WDTE:
Watchdog Timer Enable bit
1
= WDT enabled
0
= WDT disabled
FOSC1:FOSC0:
Oscillator Selection bits
00
= LP oscillator
01
= XT oscillator
10
= HS oscillator
11
= RC oscillator
Note 1:
Refer to the PIC16F54, PIC16F57 and PIC16F59 Programming Specifications to determine how
to access the Configuration Word. These documents can be found on the Microchip web site at
www.microchip.com.
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = bit is cleared
x = bit is unknown
bit 2:
bit 1-0:
©
2007 Microchip Technology Inc.
DS41213D-page 37
MICROCHIP [ MICROCHIP TECHNOLOGY ]
