Code-Hopping Decoder Helps Make Access Control Systems Secure

Providing a high level of security in remote-keyless-entry (RKE) and access control applications, the HCS515 KEELOQ code-hopping decoder offloads all timing and processing-intensive functions from the system µC. The device provides a complete decoder solution that handles reception and validation of codes and learning of new transmitters. Accommodating up to seven transmitters, the HCS515 provides encrypted storage of manufacturers' and transmitter keys and storage of other transmitter parameters. The decoder's 1-Kbit of EEPROM can be accessed through the same two-wire interface used to communicate with the decoder. The device uses the S_DAT and S_CLD inputs to communicate with host-controlled devices. A 4-MHz on-board oscillator eliminates the need for external components.