PIC16C620A-04I/SO View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16C620A-04I/SO

EPROM-Based 8-Bit CMOS Microcontrollers

Microchip Technology 

PIC16C62X

9.3 RESET

The PIC16C62X differentiates between various kinds

of RESET:

a) Power-on Reset (POR)

b) MCLR Reset during normal operation

c) MCLR Reset during SLEEP

d) WDT Reset (normal operation)

e) WDT wake-up (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, WDT Reset and MCLR Reset during

SLEEP. 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 9-2.

These bits are used in software to determine the nature

of the RESET. See Table 9-5 for a full description of

RESET states of all registers.

A simplified block diagram of the on-chip RESET circuit

is shown in Figure 9-6.

The MCLR Reset path has a noise filter to detect and

ignore small pulses. See Table 12-5 for pulse width

specification.

FIGURE 9-6:

SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT

External

RESET

MCLR/

VPP Pin

VDD

WDT

Module

SLEEP

WDT

Time-out

Reset

VDD rise

detect

Power-on Reset

Brown-out

Reset BODEN

OST/PWRT

OST

10-bit Ripple-counter

OSC1/

CLKIN

Pin

On-chip(1)

RC OSC

PWRT

10-bit Ripple-counter

S

Q

Chip_Reset

R

Q

Enable PWRT

Enable OST

See Table 9-1 for time-out situations.

Note 1: This is a separate oscillator from the RC oscillator of the CLKIN pin.

 2003 Microchip Technology Inc.

DS30235J-page 49

Share Link: