HCS360-IP datasheet(10/24 Pages) MICROCHIP

10 / 24 page

HCS360

DS40152C-page 10

Preliminary

3.5.10

MANCH: MANCHESTER CODE

MODULATION

MANCH selects between Manchester code modulation

and PWM modulation. If MANCH = 1, Manchester code

modulation is selected:

If MANCH = 0, PWM modulation is selected.

3.5.11

OVR: OVERFLOW

The overﬂow bit is used to extend the number of possi-

ble

synchronization

values.

The

synchronization

counter is 16 bits in length, yielding 65,536 values

before the cycle repeats. Under typical use of

10 operations a day, this will provide nearly 18 years of

use before a repeated value will be used. Should the

system designer conclude that is not adequate, then

the overﬂow bit can be utilized to extend the number of

unique values. This can be done by programming OVR

to 1 at the time of production. The encoder will automat-

ically clear OVR the ﬁrst time that the transmitted syn-

chronization value wraps from 0xFFFF to 0x0000.

Once cleared, OVR cannot be set again, thereby creat-

ing a permanent record of the counter overﬂow. This

prevents fast cycling of 64K counter. If the decoder sys-

tem is programmed to track the overﬂow bits, then the

effective number of unique synchronization values can

be extended to 128K. If programmed to zero, the sys-

tem will be compatible with the NTQ104/5/6 devices

(i.e., no overﬂow with discrimination bits set to zero).

4.0

TRANSMITTED WORD

4.1

Transmission Format (PWM)

The HCS360 transmission is made up of several parts

(Figure 4-1 and Figure 4-2). Each transmission is

begun with a preamble and a header, followed by the

encrypted and then the ﬁxed data. The actual data is

67 bits which consists of 32 bits of encrypted data and

35 bits of ﬁxed data. Each transmission is followed by

a guard period before another transmission can begin.

Refer to Table 8-4 and Table 8-5 for transmission timing

speciﬁcations. The encrypted portion provides up to

four billion changing code combinations and includes

the function bits (based on which buttons were acti-

vated) along with the synchronization counter value

and discrimination value. The non-encrypted portion is

comprised of the CRC bits, VLOW bits, the function bits

and the 28/32-bit serial number. The encrypted and

non-encrypted sections combined increase the number

of combinations to 1.47 x 1020.

4.2

Code Word Organization

The HCS360 transmits a 67-bit code word when a but-

ton is pressed. The 67-bit word is constructed from a

Fixed Code portion and an Encrypted Code portion

(Figure 4-3).

The Encrypted Data is generated from 4 function bits,

2 user bits, overﬂow bit, independent mode bit, and 8

serial number bits, and the 16-bit synchronization value

(Figure 8-4).

The Non-encrypted Code Data is made up of a VLOW

bit, 2 CRC bits, 4 function bits, and the 28-bit serial

number. If the extended serial number (32 bits) is

selected, the 4 function code bits will not be transmit-

ted.

HCS360-IP 数据表(PDF) 10 Page - Microchip Technology

HCS360-IP 数据表(HTML) 10 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

数据表下载