LSQ976-NR-1-0-20-R18 datasheet(17/50 Pages) MICROCHIP

17 / 50 page

Getting Started

 2012 Microchip Technology Inc.

DS41646A-page 17

FIGURE 2-2:

KEY FOB WITH FOUR PUSH BUTTONS

2.5.2

Embedded Security Development Board as Receiver

When the SX1239 Receiver PICtail Daughter Board receives a secured packet, the

content of the packet is acquired by the target application microcontroller. Based on the

length of the received packet, the target application microcontroller decides the cipher

(KEELOQ Classic or KEELOQ AES) that is used to secure the data. The decryption

process reveals the plain text, and the authentication process verifies whether the plain

text is valid information.

2.5.2.1

KEELOQ CLASSIC

For KEELOQ Classic, only a message from a known transmitter can be accepted by the

receiver. If a packet is received from an unknown transmitter, the message “KLQ

Transmitter Not Learned

” will be displayed on the LCD, as shown in Figure 2-3.

FIGURE 2-3:

ERROR MESSAGE OF RECEIVING PACKET FROM

UNKNOWN TRANSMITTER

To learn a transmitter, the receiver initiates the learning process by pressing button

SW4. The learning procedure will be started and the message “Learn mode active”

will be displayed on the LCD, as shown in Figure 2-4.

FIGURE 2-4:

START LEARN MODE

TopButton

LeftButton

RightButton

BottomButton

LED

LSQ976-NR-1-0-20-R18 데이터시트(PDF) 17 Page - Microchip Technology