HCS101

DS41115D-page 4

Preliminary

 1999-2013 Microchip Technology Inc.

3.0

TRANSMITTED WORD

3.1

Transmission Format (PWM Mode)

The HCS101 transmission is made up of several code

words as shown in Figure 3-1. Each code word starts

with a preamble and a header, followed by the data.

The code word is followed by a guard period before the

next code word begins. The same code word is trans-

mitted as long as the button is pressed. Refer to

Table 7-3 for transmission timing requirements.

3.2

Code Word Organization

The HCS101 transmits a 66-bit code word. The 66-bit

word is constructed from the serial numbers, counter

and function information. The code word format is

shown in Figure 3-2.

Under normal conditions, serial number 1 is transmitted

with the counter and serial number 3. If all the buttons

are pressed, serial number 2 is transmitted in place of

the counter and serial number 3.

FIGURE 3-1:

CODE WORD TRANSMISSION FORMAT

FIGURE 3-2:

CODE WORD ORGANIZATION

LOGIC ‘0’

LOGIC ‘1’

Bit

Period

Preamble

Header

Counter, SER_3

and Function

Guard

Time

Tp

Th

Tg

Start Pulse

(Te)

SER_1

and Function

Serial Number 3

(10 bits)

Transmission Direction

Serial Number 1

Function**

(0/4 bits)

(32/28 bits)**

* See Section 4.3.6, S3 Setting (S3SET)

** See Section 4.3.7 Extended Serial Number (XSER)

*** Serial Number 2 is transmitted when all buttons are pressed

LSb first

S2 S1 S0 S3*

S2 S1 S0 S3*

(16 bits)

Counter

‘00’

(2 bits)

Function

(4 bits)

‘1’

(1 bit)

(1 bit)

Serial Number 2***

(32 bits)

MSb

LSb