PIC16F636-E/P Microchip Technology, PIC16F636-E/P Datasheet - Page 2

• Manufacturer Part Number: PIC16F636-E/P
• Description: IC MCU FLASH 2KX14 14DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F636-E/P

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Peripherals: Brown-out Detect/Reset, LVD, POR, WDT
• Number Of I /o: 11
• Program Memory Size: 3.5KB (2K x 14)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 14-DIP (0.300", 7.62mm)
• For Use With: AC164039 - MODULE SKT PROMATE II 20DIP/SOICAC162057 - MPLAB ICD 2 HEADER 14DIPACICE0207 - MPLABICE 14P 300 MIL ADAPTER
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Connectivity: -

TB086
SUPPORTING FIRMWARE
REQUIREMENTS
Encryption keys and serial numbers can be stored
either in program memory or in data memory, which is
up to the user to decide. The remaining code can be
customized to implement K
and encoders as required by system specifications.
This includes, but is not limited to:
• Keeping track of the 16-bit synchronization
• Reading and debouncing button inputs.
• Controlling actual transmission output.
• Monitoring the battery voltage (i.e., using PLVD)
• Loading the pertinent information into the Code
The data format and the communications protocol must
also be customized by the end-user. Additionally, if end-
users want to implement a solution similar to an existing
K
but with more features, they should reference the
applicable K
what to store in EEPROM, how to transmit the actual
data stream, how to setup the CSR registers, mapping
how to sample and map of the input buttons and any
outputs that exist.
As one can discern, the type of transmission can be
implemented in any manner that is appropriate to
system requirements such as Pulse Code Modulation
(i.e., PWM, VPWM, PPM, Manchester, etc.). Validation
and software testing are also left to customers, as is
generating their own SQTP
handle all customer projects as either a standard QTP
or SQTP (serialized) PICmicro microcontroller design
with the same development tools and production
support that are currently available.
DS91086A-page 2
EE
counter; storing the counter in EEPROM, adding
EEPROM write error recovery schemes, and
incrementing the counter before transmitting any
new data.
(Transmissions need to be firmware controlled on
any of the available I/O pins.)
and generating user feedback (i.e., LEDs,
successful transmission or reception, etc.).
Shift Register (CSR), such as the function code,
discrimination bits, and the synchronization
counter data.
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device, such as any of the K
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device data sheet for information of
EE
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data files. Microchip will
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compatible decoders
EE
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encoders,
CODE SPACE AND TIME RESOURCES
Since these PICmicro microcontrollers can implement
the K
encoding and decoding process is typically 50 times
faster than completing the algorithm in firmware with a
processor running at the same speed (~500 μs vs.
~25 ms, with a 14-bit PICmicro microcontroller core
running at 4 MHz).
In terms of resource space, the encryption/decryption
routines typically utilize about 60 to 70 lines of code in a
PICmicro microcontroller and about 14 RAM locations.
All of these instructions and handling of volatile variables
are now handled within the hardware peripheral after it
is initialized, properly loaded and set into motion to
complete the encryption/decryption process.
CONCLUSION
This document describes the general use of the
Cryptographic module included on the PIC12F635/
PIC16F636/PIC16F639.
description of the type of supporting firmware
designers can expect to implement to effectively use
the
explanation of the necessity and process of obtaining a
licensing agreement, the application note and technical
brief relating to this module was included.
EE
Cryptographic
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algorithm in a hardware module, the actual
module
© 2005 Microchip Technology Inc.
Additionally,
was
provided.
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general
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