HCS410 datasheet(17/46 Pages) MICROCHIP

17 / 46 page

HCS410

DS40158F-page 17

2.6

IFF Special Features

2.6.1

ANTI-COLLISION (ACOLI)

When the ACOLI bit is set in the configuration word,

anti-collision mode is entered. The HCS410 will start

sending ACK pulses when it enters a magnetic field.

The ACK pulses stop as soon as the HCS410 detects

a start bit from the decoder. A ‘select encoder’ opcode

(00000) is then sent out by the decoder, followed by a

32-bit serial number. If the serial number matches the

HCS410’s serial number, the HCS410 will acknowl-

edge with the acknowledge sequence as shown in

Figure 2-18. The HCS410 can then be addressed as

normal. If the serial number does not match, the IFF

encoder will stop transmitting ACK pulses until it is

either removed from the field or the correct serial num-

ber is given.

FIGURE 2-18: SERIAL NUMBER CORRECT

ACKNOWLEDGE SEQUENCE

2.6.2

TRANSPONDER IN/RF OUT

When in transponder mode with ACOLI and XPRF set,

the outputs of the HCS410’s LC0:LC1 pins are echoed

on the PWM output line. After transmitting the data on

the LC pins, the data is then transmitted on the PWM

line. The transmission format mirrors a code hopping

transmission. The response replaces the 32-bit code

hopping portion of the transmission. If the response is

a 16-bit response, the 16 bits are duplicated to make up

the 32-bit code hopping portion. The preamble, serial

number, CRC, and queuing bits are all transmitted as

normal (Figure 2-19).

This feature will be used in applications which use RF

for long distance unidirectional authentication and short

distance IFF.

2.6.3

INTELLIGENT DAMPING

If the LC circuit on the transponder has a high Q-factor,

the circuit will keep on resonating for a long time after

the field has been shut down by the decoder. This

makes fast communication from the decoder to the

HCS410 difficult. If the IDAMP bit is set to 0, the

HCS410 will clamp the LC pins for 5 µs every 1/4 TE,

whenever the HCS410 is expecting data from the

decoder. The intelligent dumping pulses start 64 TE

after the acknowledge pulses have been sent and con-

tinue for 64 TE. If the HSC410 detects data from the

base station while sending out dump pulses, the dump

pulses will continue to be sent. This option can be set

in the configuration word.

2.7

LED Indicator

If a signal is detected on LC0, the LED pin goes high for

30 ms every 8s (IFFB = 0) or 4s (IFFB 1) to indicate that

the power source is charging.

FIGURE 2-19: IFF INDUCTIVE IN RF OUT

FIGURE 2-20: LED INDICATOR WHEN CHARGING POWER SOURCE

LC0/1

3 TE

Note:

If code word blanking is enabled, the

HCS410 will not give any ACK pulses after

a read, write or IFF.

Preamble

Header

Response

(32 bits)

Fixed Code

(37 bits)

PWM

LCI0/1

32-bit Response

16-bit

Response

16-bit

Response

Encoder

Select ACK

Opcode

(Read)

Response

(2*+16 bits)

Ack

*2-bit preamble precedes the data.

LC0

LED

IFFB = 0

LED

IFFB = 1

30 ms

*Patents have been applied for.

40158F.book Page 17 Wednesday, June 1, 2011 10:36 AM

HCS410 数据表(PDF) 17 Page - Microchip Technology

HCS410 数据表(HTML) 17 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 38 39 40 41 42 43 44 45 46

数据表下载

链接网址

HCS410 数据表(PDF) 17 Page - Microchip Technology

HCS410 数据表(HTML) 17 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 38 39 40 41 42 43 44 45 46

数据表 下载

链接网址

数据表下载