hcs365 Microchip Technology Inc., hcs365 Datasheet - Page 5

• Manufacturer Part Number: hcs365
• Description: Keeloq Code Hopping Encoder
• Manufacturer: Microchip Technology Inc.

2.0
As shown in the typical application circuits (Figure 2-1),
the HCS365 is an easy device to use. It requires only
the addition of buttons and RF circuitry for use as the
encoder in your security application. A description of
each pin is described in Table 2-1. Refer to Figure 2-2
for information on the I/O pins.
TABLE 2-1:
Note:
2002 Microchip Technology Inc.
SHIFT/
Name
RFEN
DATA
LED
V
V
S3/
S0
S1
S2
SS
DD
DEVICE DESCRIPTION
S0-S3 inputs have pull-down resistors. V
should be tied high if the step-up regulator
is not used.
Number
Pin
1
2
3
4
5
6
7
8
PIN DESCRIPTIONS
Switch input 0
Switch input 1
Switch input 2
Switch input 3,
SHIFT button or
RF Enable output
Ground reference
Data output pin/
Open drain output for LED
Positive supply voltage
Description
Preliminary
IN
The HCS365 will normally be in a low power SLEEP
mode. When a button input is taken high, the device will
wake up, start the step-up regulator, and go through the
button debounce delay of T
latched. In addition, the device will then read the con-
figuration options. Depending on the configuration
options and the button code, the device will determine
what the data and modulation format will be for the
transmission. The transmission will consist of a stream
of code words and will be transmitted T
ton is pressed for as long as the buttons are held down
or until a time-out occurs. The code word format can be
either a code hopping format or a seed format.
The time-out time can be selected with the Time-out
Select (TSEL) configuration option. This option allows
the time-out to be set to 0.8s, 3.2s, 12.8s, or 25.6s.
When a time-out occurs, the device will go into SLEEP
mode to protect the battery from draining when a button
gets stuck.
If the device is in the transmit process and detects that
a new button is pressed, the current code word will be
aborted, a new code word will be transmitted and the
time-out counter will RESET. If all the buttons are
released, a minimum number of code words will still be
completed. The minimum code words can be set to 1,
2, 4, or 8 using the Minimum Code Words (MTX) con-
figuration option. If the time for transmitting the mini-
mum code words is longer than the time-out time, the
device will not complete the minimum code words.
DB
before the button code is
HCS365
DS41109D-page 5
PU
after the but-