PIC16F610 Datasheet, PDF (110/180 Pages) Microchip Technology – 14-Pin, Flash-Based 8-Bit CMOS Microcontrollers

PIC16F610/616/16HV610/616
12.2 Calibration Bits
The 8 MHz internal oscillator is factory calibrated.
These calibration values are stored in fuses located in
the Calibration Word (2009h). The Calibration Word is
not erased when using the specified bulk erase
sequence in the “PIC12F60X/12F61X/16F61X Memory
Programming Specification” (DS41284) and thus, does
not require reprogramming.
12.3 Reset
The PIC16F610/616/16HV610/616 differentiates
between various kinds of Reset:
a) Power-on Reset (POR)
b) WDT Reset during normal operation
c) WDT Reset during Sleep
d) MCLR Reset during normal operation
e) MCLR Reset during Sleep
f) Brown-out Reset (BOR)
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.
FIGURE 12-1:
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
External
Reset
MCLR/VPP pin
VDD
WDT
Module
POR
Detect
Sleep
WDT
Time-out
Reset
Power-on Reset
Brown-out⁽¹⁾
Reset
BOREN
OSC1/
CLKI pin
OST/PWRT
OST
10-bit Ripple Counter
On-Chip
RC OSC
PWRT
11-bit Ripple Counter
S
Chip_Reset
R
Q
Note 1: Refer to the Configuration Word register (Register 12-1).
Enable PWRT
Enable OST
DS41288C-page 108
Preliminary
© 2007 Microchip Technology Inc.