PIC16F688 Datasheet, PDF (103/174 Pages) Microchip Technology – 14-Pin Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC16F688
11.2 Calibration Bits
The Brown-out Detect (BOD), Power-on Reset (POR)
and 8 MHz internal oscillator (HFINTOSC) are factory
calibrated. These calibration values are stored in the
Calibration Word, as shown in Register 11-2 and are
mapped in program memory location 2008h.
The Calibration Word is not erased when the device is
erased when using the procedure described in the
“PIC12F6XX/16F6XX Memory Programming
Specification” (DS41204). Therefore, it is not
necessary to store and reprogram these values when
the device is erased.
Note:
Address 2008h is beyond the user program
memory space. It belongs to the special
configuration memory space (2000h-
3FFFh), which can be accessed only during
programming. See “PIC12F6XX/16F6XX
Memory Programming Specification”
(DS41204) for more information.
REGISTER 11-2: CALIB – CALIBRATION WORD (ADDRESS: 2008h)
— FCAL6 FCAL5 FCAL4 FCAL3 FCAL2 FCAL1 FCAL0 —
bit 13
POR1 POR0 BOD2 BOD1 BOD0
bit 0
bit 13
bit 12-6
bit 5
bit 4-3
bit 2-0
Unimplemented: Read as ‘0’
FCAL<6:0>: Internal Oscillator Calibration bits
0111111 = Maximum frequency
.
.
0000001
0000000 = Center frequency
1111111
.
.
1000000 = Minimum frequency
Unimplemented: Read as ‘0’
POR<1:0>: POR Calibration bits
00 = Lowest POR voltage
11 = Highest POR voltage
BOD<2:0>: BOD Calibration bits
000 = Reserved
001 = Lowest BOD voltage
111 = Highest BOD voltage
Note 1: This location does not participate in bulk erase operations if the “PIC12F6XX/16F6XX Memory
Programming Specification” (DS41204) procedure is used.
2: Calibration bits are reserved for factory calibration. These values can and will change across the entire
range; therefore, specific values and available adjustment range can not be specified.
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
 2004 Microchip Technology Inc.
Preliminary
DS41203B-page 101