MCS3142-ISLASHST datasheet(21/37 Pages) MICROCHIP

21 / 37 page

 2014 Microchip Technology Inc.

DS40001747A-page 21

MCS3142

6.0

TRANSMITTER OPERATION

6.1

Data Modulation Format and Baud

Rate

A transmission is made of up several code words. Each

code word contains a preamble, header and data. A

code word is separated from another code word by

guard time.

All timing specifications for the modulation formats are

based on a basic Time Element, described as TE. See

Section 6.2 “Baud Rate” for details on baud rate

calculation. This timing element can be set to a wide

range of values. The length of the preamble, header

and guard is fixed.

The data modulation format is selected for each

encoder. See Table 3-6 for the Classic KEELOQ

encoder and Table 3-14 for Ultimate KEELOQ encoder.

FIGURE 6-1:

PWM TRANSMISSION FORMAT

FIGURE 6-2:

MANCHESTER TRANSMISSION FORMAT

116

31 TE Pre amb le

3-10 TE

Heade r

Encrypted Portion

Fixe d Cod e P orti on

Gua rd

Time

TBP

Logic ‘0’

Logic ‘1’

Rev. 20-000 003A

8/29/201 3

116

Pre amb le

Encrypted Portion

Fixe d Cod e P orti on

Gua rd

Time

TBP

Logic ‘0’

Logic ‘1’

Heade r

bit 1

bit 0

bit 2

START bit

STOP bit

Rev. 20-000 004A

8/29/201 3

MCS3142-I/ST 数据表(PDF) 21 Page - Microchip Technology

MCS3142-I/ST 数据表(HTML) 21 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37

数据表下载