DM303006 Microchip Technology, DM303006 Datasheet - Page 18

• Manufacturer Part Number: DM303006
• Description: KIT EVALUATION KEELOQ
• Manufacturer: Microchip Technology
• Series: KEELOQ®r
• Type: KeeLoq®r

Specifications of DM303006

• Silicon Manufacturer: Microchip
• Kit Contents: Main Board, 2 Transmitters, Cables And Power Supply
• Tool / Board Applications: General Purpose MCU, MPU, DSP, DSC
• For Use With: KeeLoq
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification
• For Use With/related Products: Keeloq Encoders & Decoders
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Request inventory verification / Request inventory verification

K
In addition, provisions must be made for counter dis-
crepancies caused by a user activating the transmitter
while out of range of the decoder. K
accommodate this by providing two synchronization
windows. If the synchronization counter received is 1 to
16 counts above the stored counter, the decoder
accepts the transmission as a valid transmission,
updates the stored counter and activates the appropri-
ate output. If the synchronization counter received is
between 16 and 32k counts above the stored counter,
the decoder temporarily stores the received counter
and waits for a second transmission. The second trans-
mission’s counter is compared to the temporary
counter. If they are consecutive, the decoder re-syn-
chronizes by storing the latest counter and activates
the appropriate output. Counter values outside of these
windows, 32k – 64k counts above the stored counter
value, are considered invalid and these transmissions
are ignored.
5.1.2
The encoder is activated when one or more of the
encoder inputs (S0, S1, S2, S3) is pulled HIGH. The
function code (“button code”) is one part of the trans-
mitted code word. The function code mirrors the
encoder inputs and may be used to activate specific
functions of a multifunction decoder. For example, S0
could be used to deactivate the alarm and unlock the
car, S1 to open the trunk and when pressed together
they activate a panic function.
5.1.3
Various modulation formats can be selected for the
encoder data output signal. All K
a Pulse Width Modulation (PWM) format. In addition,
encoders like the HCS360 and HCS362 offer
Manchester Encoding and the HCS361 and HCS365
offer Variable Pulse Width Modulation (VPWM).
Every encoder offers multiple transmission Baud
Rates; expressed in terms of the an elementary time
element (T
est Baud Rate pulse width of 800 µs to a fastest Baud
Rate pulse width of 100 µs. The number of Baud Rate
options and exact values vary with the chosen encoder
model.
DS41155A-page 16
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ENCODER ACTIVATION
TRANSMISSION BAUD RATES AND
MODULATION FORMATS
) duration. T
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EVALUATION KIT II USER’S GUIDE
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typically ranges from a slow-
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encoders offer
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decoders
5.1.4
The K
of operating voltages. Most models operate from 2V to
6V which is ideal for applications using one or two 3V
lithium batteries. Selected models operate directly from
a 9V to 12V battery which is convenient for applica-
tions where a standard 9V battery or a common 12V
(type GP23) battery is used.
5.1.5
All K
each transmission. The bit is set when the encoder
detects the supply voltage has dropped below a set
threshold. This allows the decoder/receiver to indicate
when the transmitter battery needs replacement. Con-
sult the individual encoder data sheets for the exact
threshold levels available.
5.1.6
A 16-bit synchronization counter, minimum, is incre-
mented, encrypted, and transmitted each time the
encoder is activated. The 16-bit length of the synchro-
nization counter allows 10 activations per day for 18
years before the cycle begins to repeat. Should the
system designer conclude this is not adequate, then
the overflow bits can be used to extend this cycle. One
of the two overflow bits is cleared each time the counter
wraps
bles the range of the synchronization counter and uti-
lizing both triples the range of the synchronization
counter.
5.1.7
An auto-shutoff function is available on K
ers. If enabled, the auto-shutoff function stops the
device from transmitting if a button is continuously
pressed for a long period of time. This prevents the
encoder from draining the battery if a button is acciden-
tally pressed while in a pocket or purse. The time-out
period is typically 25 seconds but some devices have
shorter or programmable time-out periods essential for
certification in some countries.
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OPERATING VOLTAGE
LOW VOLTAGE DETECTION
encoders include a low voltage status bit in
COUNTER OVERFLOW
AUTO-SHUTOFF
. Therefore, utilizing one overflow bit dou-
encoder product line covers a wide range
 2001 Microchip Technology Inc.
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encod-