PIC12F683-E/MD MICROCHIP [Microchip Technology], PIC12F683-E/MD Datasheet - Page 87

• Manufacturer Part Number: PIC12F683-E/MD
• Description: 8-Pin Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

12.2
Brown-out Reset (BOR), Power-on Reset (POR) and
8 MHz internal oscillator (HFINTOSC) are factory cali-
brated. These calibration values are stored in fuses
located in the Calibration Word (2009h). The Calibra-
tion Word is not erased when using the specified bulk
erase sequence in the “PIC12F6XX/16F6XX Memory
Programming Specification” (DS41244) and thus, does
not require reprogramming.
12.3
The PIC12F683 differentiates between various kinds of
Reset:
a)
b)
c)
d)
e)
f)
FIGURE 12-1:
© 2007 Microchip Technology Inc.
MCLR/V
Note 1: Refer to the Configuration Word register (Register 12-1).
Power-on Reset (POR)
WDT Reset during normal operation
WDT Reset during Sleep
MCLR Reset during normal operation
MCLR Reset during Sleep
Brown-out Reset (BOR)
CLKI pin
OSC1/
V
DD
Calibration Bits
Reset
PP
pin
LFINTOSC
OST/PWRT
Brown-out
V
Module
Detect
DD
WDT
Reset
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
Rise
OST
PWRT
(1)
10-bit Ripple Counter
WDT
Time-out
Reset
11-bit Ripple Counter
SBOREN
BOREN
Power-on Reset
External
Reset
SLEEP
Some registers are not affected in any Reset condition;
their status is unknown on POR and unchanged in any
other Reset. Most other registers are reset to a “Reset
state” on:
• Power-on Reset
• MCLR Reset
• MCLR Reset during Sleep
• WDT Reset
• Brown-out Reset (BOR)
WDT wake-up does not cause register resets in the
same manner as a WDT Reset since wake-up is
viewed as the resumption of normal operation. TO and
PD bits are set or cleared differently in different Reset
situations, as indicated in Table 12-2. Software can use
these bits to determine the nature of the Reset. See
Table 12-4 for a full description of Reset states of all
registers.
A simplified block diagram of the On-Chip Reset Circuit
is shown in Figure 12-1.
The MCLR Reset path has a noise filter to detect and
ignore small pulses. See Section 15.0 “Electrical
Specifications” for pulse-width specifications.
Enable PWRT
Enable OST
PIC12F683
S
R
DS41211D-page 85
Q
Chip_Reset