HTRM440 Просмотр технического описания (PDF) - Philips Electronics

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HTRM440

HITAG proximity reader module hardware

Philips Electronics 

Philips Semiconductors

HITAG proximity reader module

hardware

Product specification

HTRM440 family

7.2 Reader module software

Software commands mentioned in this data sheet are fully

described in document “HTCM400, HTRM440 Family,

HTRM800 Family Interface Protocol Reader - Host”.

7.3 Reader module hardware

7.3.1 CORE MODULE

The EEPROM on the core module HTCM400 (see Fig.1)

is used to store non-volatile data such as personalization

data, keys, passwords, configurations and status

information.

The microcontroller processes the protocol for the

communication between the transponders and the reader

module. The interface signals are converted in such a way

that HITAG 1 and HITAG 2 transponders are able to

process them and the outgoing signals from the

transponder are converted into interface-compatible

signals. The second essential microcontroller function is

its control function. The microcontroller activates and

deactivates the transmitter, switches the receiver between

the modes for the different transponders reception and

selects the EEPROM.

The transmitter receives data from the microcontroller and

modulates the carrier.

The receiver demodulates the received data and passes

on the data to the microcontroller for further processing.

7.3.2 INTERFACE MICROCONTROLLER TO HOST

The device communicates with the host

(e.g. microcontroller or PC) via a serial interface using a

baud rate of 9600 baud. Data transfer details are: 1 start

bit, 8 data bits, 1 stop bit, no parity bit and the least

significant bit is sent first.

7.3.3 VOLTAGE REGULATION FILTERING

Disturbances on the supply pins may reduce the

performance of the system. For that reason the supply

voltage is filtered but also to limit the spurious emissions at

the supply connections caused by the digital parts of the

module.

7.4 Postal approval

The postal approval can only be granted for final products,

not just for modules like the HTRM440. But the reader

module is designed in a way that it is possible to get the

postal approval for a system including the HTRM440.

Electromagnetic emissions comply with the guidelines in

FTZ 17 TR 2100 and ETS 300 683 and electromagnetic

immunity complies with the guidelines in ETS 300 683.

7.5 Security considerations

Developing the HTRM440 special consideration was given

to aspects of security. The following items represent the

fundamental framework of the security concept:

• Cryptography

• Mutual authentication

• Password verification

• Cyclic Redundancy Check (CRC).

7.5.1

DATA STREAM BETWEEN READER MODULE AND

HITAG 1 TRANSPONDERS

All the commands and data transferred from the reader

module to the transponder are secured by Cyclic

Redundancy Check (CRC). This check is carried out on

the transponder.

Every data stream sent (commands, addresses, user

data) from the proximity reader module to the transponder

is first checked for data errors by the transponder by

means of an integrated 8-bit CRC generator and then

executed. Normally the transponder responds to each

data stream from the proximity reader module with an

acknowledgement signal or with a data block. The CRC is

formed over commands and addresses or the plain data

respectively and in case of crypto mode it is also

encrypted. The generator polynomial of the transponder

CRC generator reads: u8 + u4 + u3 + u2 +1 = 0x1D.

The CRC pre assignment is 0xFF.

Detailed instructions how to use and calculate CRC are

available at Philips in the following application note

“HT1 (resp. HT2) Transponder family, reliability and

integrity of data transmission”.

7.5.2

DATA STREAM BETWEEN READER MODULE AND

HITAG 2 TRANSPONDERS

Every command sent from the reader module to the

transponder is checked for data errors by the transponder.

Standard commands transferred from the reader module

to the transponder are divided into two bit streams. The

second bit stream is generated by inverting the bits of the

first bit stream. This redundancy increases data security.

2001 Oct 04

7

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