Datasheet

PIC17C7XX
DS30289C-page 192  1998-2013 Microchip Technology Inc.
17.1 Configuration Bits
The PIC17CXXX has eight configuration locations
(Table 17-1). These locations can be programmed
(read as '0'), or left unprogrammed (read as '1') to
select various device configurations. Any write to a
configuration location, regardless of the data, will pro-
gram that configuration bit. A TABLWT instruction and
raising the MCLR
/VPP pin to the programming voltage
are both required to write to program memory loca-
tions. The configuration bits can be read by using the
TABLRD instructions. Reading any configuration loca-
tion between FE00h and FE07h will read the low byte
of the configuration word (Figure 17-1) into the TAB-
LATL register. The TABLATH register will be FFh.
Reading a configuration location between FE08h and
FE0Fh will read the high byte of the configuration word
into the TABLATL register. The TABLATH register will
be FFh.
Addresses FE00h through FE0Fh are only in the pro-
gram memory space for Microcontroller and Code Pro-
tected Microcontroller modes. A device programmer
will be able to read the configuration word in any pro-
cessor mode. See programming specifications for
more detail.
TABLE 17-1: CONFIGURATION
LOCATIONS
17.2 Oscillator Configurations
17.2.1 OSCILLATOR TYPES
The PIC17CXXX can be operated in four different oscil-
lator modes. The user can program two configuration
bits (FOSC1:FOSC0) to select one of these four
modes:
• LF Low Power Crystal
• XT Crystal/Resonator
• EC External Clock Input
• RC Resistor/Capacitor
For information on the different oscillator types and
how to use them, please refer to Section 4.0.
Bit Address
FOSC0 FE00h
FOSC1 FE01h
WDTPS0 FE02h
WDTPS1 FE03h
PM0 FE04h
PM1 FE06h
BODEN FE0Eh
PM2 FE0Fh
Note: When programming the desired configura-
tion locations, they must be programmed
in ascending order, starting with address
FE00h.