1996 Microchip Technology Inc.
DS30412C-page 5
PIC17C4X
1.0
OVERVIEW
This data sheet covers the PIC17C4X group of the
PIC17CXX family of microcontrollers. The following
devices are discussed in this data sheet:
PIC17C42
PIC17CR42
PIC17C42A
PIC17C43
PIC17CR43
PIC17C44
The
PIC17CR42,
PIC17C42A,
PIC17C43,
PIC17CR43, and PIC17C44 devices include architec-
tural
enhancements
over
the
PIC17C42. These
enhancements will be discussed throughout this data
sheet.
The
PIC17C4X
devices
are
40/44-Pin,
EPROM/ROM-based
members
of
versatile
PIC17CXX
family
of
low-cost,
high-performance,
CMOS, fully-static, 8-bit microcontrollers.
All PIC16/17 microcontrollers employ an advanced
RISC architecture. The PIC17CXX has enhanced core
features, 16-level deep stack, and multiple internal and
external interrupt sources. The separate instruction and
data buses of the Harvard architecture allow a 16-bit
wide instruction word with a separate 8-bit wide data.
The two stage instruction pipeline allows all instructions
to execute in a single cycle, except for program
branches (which require two cycles). A total of 55
instructions (reduced instruction set) are available in
the PIC17C42 and 58 instructions in all the other
devices. Additionally, a large register set gives some of
the architectural innovations used to achieve a very
high performance. For mathematical intensive applica-
tions all devices, except the PIC17C42, have a single
cycle 8 x 8 Hardware Multiplier.
PIC17CXX microcontrollers typically achieve a 2:1
code compression and a 4:1 speed improvement over
other 8-bit microcontrollers in their class.
PIC17C4X devices have up to 454 bytes of RAM and
33 I/O pins. In addition, the PIC17C4X adds several
peripheral features useful in many high performance
applications including:
Four timer/counters
Two capture inputs
Two PWM outputs
A Universal Synchronous Asynchronous Receiver
Transmitter (USART)
These special features reduce external components,
thus reducing cost, enhancing system reliability and
reducing power consumption. There are four oscillator
options, of which the single pin RC oscillator provides a
low-cost solution, the LF oscillator is for low frequency
crystals and minimizes power consumption, XT is a
standard crystal, and the EC is for external clock input.
The SLEEP (power-down) mode offers additional
power saving. The user can wake-up the chip from
SLEEP through several external and internal interrupts
and device resets.
There are four conguration options for the device oper-
ational modes:
Microprocessor
Microcontroller
Extended microcontroller
Protected microcontroller
The microprocessor and extended microcontroller
modes allow up to 64K-words of external program
memory.
A highly reliable Watchdog Timer with its own on-chip
RC oscillator provides protection against software mal-
function.
Table 1-1 lists the features of the PIC17C4X devices.
A UV-erasable CERDIP-packaged version is ideal for
code development while the cost-effective One-Time
Programmable (OTP) version is suitable for production
in any volume.
The PIC17C4X ts perfectly in applications ranging
from precise motor control and industrial process con-
trol to automotive, instrumentation, and telecom appli-
cations. Other applications that require extremely fast
execution of complex software programs or the exibil-
ity of programming the software code as one of the last
steps of the manufacturing process would also be well
suited. The EPROM technology makes customization
of application programs (with unique security codes,
combinations, model numbers, parameter storage,
etc.) fast and convenient. Small footprint package
options make the PIC17C4X ideal for applications with
space limitations that require high performance. High
speed execution, powerful peripheral features, exible
I/O, and low power consumption all at low cost make
the PIC17C4X ideal for a wide range of embedded con-
trol applications.
1.1
Family and Upward Compatibility
Those
users
familiar
with
the
PIC16C5X
and
PIC16CXX families of microcontrollers will see the
architectural enhancements that have been imple-
mented. These enhancements allow the device to be
more efcient in software and hardware requirements.
Please refer to Appendix A for a detailed list of
enhancements and modications. Code written for
PIC16C5X or PIC16CXX can be easily ported to
PIC17CXX family of devices (Appendix B).
1.2
Development Support
The PIC17CXX family is supported by a full-featured
macro assembler, a software simulator, an in-circuit
emulator, a universal programmer, a “C” compiler, and
fuzzy logic support tools.
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