PCF7941ATJ Datasheet - NXP Semiconductors.

GENERAL DESCRIPTION
The PCF7x41ATJ is a high performance single chip Security Transponder and RISC Controller, ideally suited for automotive applications with combined vehicle Immobilization and Remote Keyless Entry functions.

FEATURES
• Single chip Security Transponder and Remote Keyless
   Entry solution
• RISC programmable device features
• Up to seven Keyless Entry command buttons
• 512 Byte EEPROM for extended data storage
• 32 bit unique device and product type identification
• Package integrated Transponder LF coil

Security Transponder
• Transponder operation like PCF7936 family
• Fast mutual authentication, 39ms (48 bit Secret Key)
• EEPROM read/write protection capability
• RISC programmable transponder extensions

Calculation Unit
• Hardwired security algorithm
• 48 (96) bit Secret Key

RISC Controller and Peripherals
• 8 Bit RISC Architecture (MRK )
• 4 kByte E-ROM respectively ROM (application)
• 4 kByte ROM (device firmware and library functions)
• 128 Byte User RAM
• 11 general purpose I/O (incl. 7 command button inputs)
• Two 8 Bit Timer/Counter
• Optional external clock input for Timer/Counter
• Watchdog
• Single level interrupt architecture
• On-chip RC Oscillator (< 8%)
• Short instruction execution time (as fast as 0.5 s)
• Programmable battery low detection
• Low power consumption
   RUN: 300 A, IDLE: 20A, PD: 100 nA
• Single Lithium cell operation, 2.1V to 3.6V