PIC12F635-E/MD MICROCHIP [Microchip Technology], PIC12F635-E/MD Datasheet - Page 133

• Manufacturer Part Number: PIC12F635-E/MD
• Description: 8/14-Pin, Flash-Based 8-Bit CMOS Microcontrollers with nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

12.2
The PIC12F635/PIC16F636/639 differentiates between
various kinds of Reset:
a)
b)
c)
d)
e)
f)
g)
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
FIGURE 12-1:
© 2007 Microchip Technology Inc.
Note 1:
MCLR/V
Power-on Reset (POR)
Wake-up Reset (WUR)
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
Reset
DD
PP
pin
Refer to the Configuration Word register (Register 12-1).
LFINTOSC
OST/PWRT
Brown-out
V
Module
DD
Detect
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
WDT
Reset
Rise
BOREN<0>
OST
PWRT
SBOREN
(1)
10-bit Ripple Counter
WDT
Time-out
Reset
11-bit Ripple Counter
BOREN
External Reset
Power-on Reset
Sleep
<1>
PIC12F635/PIC16F636/639
Wake-up Interrupt
RA3 Change
They are not affected by a WDT wake-up since this 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 12-3. These bits are
used in software 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.
WURE
Sleep
Enable PWRT
Enable OST
S
R
DS41232D-page 131
Q
Chip_Reset