RFHCS362F-I/SO View Datasheet(PDF) - Microchip Technology

Part Name

Description

MFG CO.

RFHCS362F-I/SO

KEELOQ® Code Hopping Encoder with UHF ASK/FSK Transmitter

Microchip Technology 

rfHCS362G/362F

4.5.12 HEADER

When PWM mode is selected the header length (low

time between preamble and data bits start) can be set

to 10 x TE or 3 x TE. The 10 x TE mode is recommended

for compatibility with previous KEELOQ encoder mod-

els. In Manchester mode, the header length is fixed and

set to 4 x TE.

4.5.13 RFEN

RFEN selects whether the RFEN output is enabled or

disabled. If enabled, S3 is only sampled 2 s after the

last button is released and at the start of the first trans-

mission. If disabled S3 functions the same as the other

S inputs. For typical implementation of the rfHCS362G/

362F the RFEN bit = 0.

4.6 SYNCHRONOUS MODE

In Synchronous mode, the code word can be clocked

out on DATA using S2 as a clock. To enter Synchro-

nous mode, S2 must be taken HIGH and then DATA

and S0 or S1 are taken HIGH. After Synchronous mode

is entered, DATA and S2 must be taken LOW. The data

is clocked out on DATA on every falling edge of S2.

Auto-shutoff timer is not disabled in Synchronous

mode. Refer to Figure 4-1 and Figure 4-2.

FIGURE 4-1:

SYNCHRONOUS TRANSMISSION MODE

TPS TPH1 TPH2

DATA

t = 50ms 35 pulses on S2 Preamble

Header

Data

S2

S0 or S1

“01,10,11”

RFEN

TRFON

FIGURE 4-2:

CODE WORD ORGANIZATION (SYNCHRONOUS TRANSMISSION MODE)

Fixed Portion

Encrypted Portion

QUEUE CRC Vlow Button

(2 bits) (2 bits) (1-bit) Status

S2 S1 S0 S3

MSb

Serial Number

(28 bits)

Button

Status

S2 S1 S0 S3

DISC+ OVR Sync Counter

(12 bits)

(16 bits)

69 Data bits

LSb

Transmitted

LSb first.

DS41189B-page 24

© 2011 Microchip Technology Inc.

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