PIC16HV540 Microchip Technology, PIC16HV540 Datasheet - Page 31

• Manufacturer Part Number: PIC16HV540
• Description: Enhanced PIC16C54 EPROM-Based 8-Bit CMOS Microcontroller
• Manufacturer: Microchip Technology

7.0
What sets a microcontroller apart from other proces-
sors are special circuits that deal with the needs of real-
time applications. The PIC16HV540 family of micro-
controllers has a host of such features intended to max-
imize
elimination of external components, provide power sav-
ing operating modes and offer code protection. These
features are:
• Oscillator selection
• Reset
• Power-On Reset (POR)
• Brown-out Detect
• Device Reset Timer (DRT)
• Wake-up from SLEEP on Pin Change
• Enhanced Watchdog Timer (WDT)
• SLEEP
• Code protection
The PIC16HV540 Family has a Watchdog Timer which
can be shut off only through configuration bit WDTEN.
It runs off of its own RC oscillator for added reliability.
There is an 18 ms delay provided by the Device Reset
Timer (DRT), intended to keep the chip in reset until the
crystal oscillator is stable. With this timer on-chip, most
applications need no external reset circuitry.
REGISTER 7-1: CONFIGURATION WORD FOR PIC16HV540
2000 Microchip Technology Inc.
bit11
bit 11-3: CP: Code Protection bits
bit 2:
bit 1-0: F
Note 1: Refer to the PIC16C5X Programming Specification (Literature number DS30190) to determine how to
CP
system
SPECIAL FEATURES OF THE
CPU
CP
1 = Code protection off
0 = Code protection on
WDTEN: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled (control is placed on the SWDTEN bit)
11 = RC oscillator
10 = HS oscillator
01 = XT oscillator
00 = LP oscillator
access the configuration word.
OSC
reliability,
<1:0>: Oscillator Selection bits
CP
CP
minimize
CP
CP
cost
CP
through
Preliminary
CP
CP
The SLEEP mode is designed to offer a very low cur-
rent power-down mode. The user can wake up from
SLEEP through external reset or through a Watchdog
Timer time-out. Several oscillator options are also
made available to allow the part to fit the application.
The RC oscillator option saves system cost while the
LP crystal option saves power. A set of configuration
bits are used to select various options.
7.1
Configuration bits can be programmed to select various
device configurations. Two bits are for the selection of
the oscillator type and one bit is the Watchdog Timer
enable bit. Nine bits are code protection bits (Figure 7-
1) for the PIC16HV540 devices.
WDTEN
Configuration Bits
F
OSC
1
PIC16HV540
F
OSC
bit0
0
Register:CONFIG
Address
DS40197B-page 31
(1)
:0FFFh