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PIC17C75X Datasheet, PDF (178/320 Pages) Microchip Technology – High-Performance 8-Bit CMOS EPROM Microcontrollers | |||
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PIC17C75X
17.1 Conï¬guration Bits
The PIC17CXXX has eight conï¬guration locations
(Table 17-1). These locations can be programmed
(read as '0') or left unprogrammed (read as '1') to select
various device conï¬gurations. Any write to a conï¬gura-
tion location, regardless of the data, will program that
conï¬guration bit. A TABLWT instruction is required to
write to program memory locations. The conï¬guration
bits can be read by using the TABLRD instructions.
Reading any conï¬guration location between FE00h
and FE07h will read the low byte of the conï¬guration
word (Figure 17-1) into the TABLATL register. The TAB-
LATH register will be FFh. Reading a conï¬guration
location between FE08h and FE0Fh will read the high
byte of the conï¬guration word into the TABLATL regis-
ter. The TABLATH register will be FFh.
Addresses FE00h thorough 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 conï¬guration word in any pro-
cessor mode. See programming speciï¬cations for
more detail.
TABLE 17-1: CONFIGURATION
LOCATIONS
Bit
FOSC0
FOSC1
WDTPS0
WDTPS1
PM0
PM1
BODEN
PM2
Address
FE00h
FE01h
FE02h
FE03h
FE04h
FE06h
FE0Eh
FE0Fh
17.2 Oscillator Conï¬gurations
17.2.1 OSCILLATOR TYPES
The PIC17CXXX can be operated in four different oscil-
lator modes. The user can program two conï¬guration
bits (FOSC1:FOSC0) to select one of these four
modes:
⢠LF
⢠XT
⢠EC
⢠RC
Low Power Crystal
Crystal/Resonator
External Clock Input
Resistor/Capacitor
For information on the different oscillator types and
how to use them, please refer to Section 4.0.
Note:
When programming the desired conï¬gura-
tion locations, they must be programmed
in ascending order. Starting with address
FE00h.
DS30264A-page 178
Preliminary
© 1997 Microchip Technology Inc.
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