© 1997 Microchip Technology Inc.

Preliminary

DS40153B-page 1

M

HCS500

FEATURES

Security

• Encrypted storage of manufacturer’s code

• Encrypted storage of encoder keys

• Up to seven transmitters can be learned

• Normal and secure learning mechanisms

Operating

• 3.0V—5.5V operation

• Internal oscillator

• Auto bit rate detection

Other

• Stand-alone decoder chipset

• External EEPROM for transmitter storage

• Synchronous serial interface

• 1 Kbit user EEPROM

• 8-pin DIP/SOIC package

Typical Applications

• Automotive remote entry systems

• Automotive alarm systems

• Automotive immobilizers

• Gate and garage openers

• Electronic door locks

• Identity tokens

• Burglar alarm systems

Compatible Encoders

• HCS200, HCS300, HCS301, HCS360,

HCS410 (PWM Mode)

DESCRIPTION

The Microchip Technology Inc. HCS500 is a code hop-

ping decoder designed for secure Remote Keyless

Entry (RKE) systems. The HCS500 utilizes the pat-

learning mechanisms to make this a canned solution

when used with the HCS encoders to implement a uni-

directional remote and access control systems. The

HCS500 can be used as a stand-alone decoder or in

conjunction with a microcontroller.

PACKAGE TYPE

BLOCK DIAGRAM

The manufacturer’s code, encoder keys, and synchro-

nization information are stored in encrypted form in

external EEPROM. The HCS500 uses the S_DAT and

S_CLK inputs to communicate with a host controller

device.

The HCS500 operates over a wide voltage range of

3.0 volts to 5.5 volts. The decoder employs automatic

bit-rate detection, which allows it to compensate for

wide variations in transmitter data rate. The decoder

contains sophisticated error checking algorithms to

ensure only valid codes are accepted.

PDIP, SOIC

1

2

3

4

EE_CLK

EE_DAT

MCLR

8

7

6

5

RFIN

S_CLK

S_DAT

67-bit Reception Register

External

CONTROL

DECRYPTOR

RFIN

OSCILLATOR

S_DAT

S_CLK

MCLR

EEPROM

EE_DAT

EE_CLK

Code Hopping Decoder

*Code hopping patents issued in Europe, U.S.A; and R.S.—US:5,517,187; Europe: 0459781