The MC68HC908RF2 MCU is a member of the low-cost, high-performance M68HC08 Family of 8-bit microcontroller units (MCUs). Optimized for low-power operation and available in a small 32-pin low-profile quad flat pack (LQFP), this MCU is well suited for remote keyless entry (RKE) transmitter designs.
All MCUs in the family use the enhanced M68HC08 central processor unit (CPU08) and are available with a variety of modules, memory sizes and types, and package types.
Features:
◆Features MCU include:• High-performance M68HC08 architecture• Fully upward-compatible object code with M6805, M146805, and M68HC05 Families• Maximum internal bus frequency of 4 MHz at 3.3 volts• Maximum internal bus frequency of 2 MHz at 1.8 volts• Internal oscillator requiring no external components:– Software selectable bus frequencies– ± 25 percent accuracy with trim capability to ±2 percent– Option to allow use of external clock source or external crystal/ceramic resonator• 2 Kbytes of on-chip FLASH memory• FLASH program memory security(1)• 128 bytes of on-chip RAM• 16-bit, 2-channel timer interface module (TIM)• 12 general-purpose input/output (I/O) ports:– Six shared with keyboard wakeup function– Two shared with the timer module– Port A pins have 3-mA sink capabilities• Low-voltage inhibit (LVI) module:– 1.85-V detection forces MCU into reset– 2.0-V detection sets indicator flag• 6-bit keyboard interrupt with wakeup feature• External asynchronous interrupt pin with internal pullup (IRQ )• Ultra high frequency (UHF) transmitter• System protection features:– Computer operating properly (COP) reset– Low-voltage detection with reset– Illegal opcode detection with reset– Illegal address detection with reset• 32-pin plastic LQFP package• Low-power design with stop and wait modes• Master reset pin and power-on reset (POR)• –40°C to 85°C and –40°C to 125°C operation◆Features of the CPU08 include:• Enhanced HC05 programming model• Extensive loop control functions• 16 addressing modes (eight more than the HC05)• 16-bit index register and stack pointer• Memory-to-memory data transfers• Fast 8 × 8 multiply instruction• Fast 16/8 divide instruction• Binary-coded decimal (BCD) instructions• Optimization for controller applications• Third party C language support
Applications:
•Object code fully upward-compatible with M68HC05 Family•16-bit stack pointer with stack manipulation instructions•16-bit index register with x-register manipulation instructions•8-MHz CPU internal bus frequency•64-Kbyte program/data memory space•16 addressing modes•Memory-to-memory data moves without using accumulator•Fast 8-bit by 8-bit multiply and 16-bit by 8-bit divide instructions•Enhanced binary-coded decimal (BCD) data handling•Modular architecture with expandable internal bus definition for extension ofaddressing range beyond 64 Kbytes•Low-power stop and wait modes
