GENERAL DESCRIPTION
The PIC12F508/509/16F505 devices from Microchip Technology are low-cost, high-performance, 8-bit, fully-static, Flash-based CMOS microcontrollers. They employ a RISC architecture with only 33 single-word/ single-cycle instructions. All instructions are single cycle (200 μs) except for program branches, which take two cycles. The PIC12F508/509/16F505 devices deliver performance an order of magnitude higher than their competitors in the same price category. The 12-bit wide instructions are highly symmetrical, resulting in a typical 2:1 code compression over other 8-bit microcontrollers in its class. The easy to use and easy to remember instruction set reduces development time significantly.
   
High-Performance RISC CPU:
• Only 33 Single-Word Instructions to Learn
• All Single-Cycle Instructions Except for Program
    Branches, which are Two-Cycle
• 12-Bit Wide Instructions
• 2-Level Deep Hardware Stack
• Direct, Indirect and Relative Addressing modes
    for Data and Instructions
• 8-Bit Wide Data Path
• 8 Special Function Hardware Registers
• Operating Speed:
    - DC – 20 MHz clock input (PIC16F505 only)
    - DC – 200 ns instruction cycle (PIC16F505
        only)
    - DC – 4 MHz clock input
    - DC – 1000 ns instruction cycle
    Special Microcontroller Features:
• 4 MHz Precision Internal Oscillator:
    - Factory calibrated to ±1%
• In-Circuit Serial Programming™ (ICSP™)
• In-Circuit Debugging (ICD) Support
• Power-On Reset (POR)
• Device Reset Timer (DRT)
• Watchdog Timer (WDT) with Dedicated On-Chip
    RC Oscillator for Reliable Operation
• Programmable Code Protection
• Multiplexed MCLR Input Pin
• Internal Weak Pull-Ups on I/O Pins
• Power-Saving Sleep mode
• Wake-Wp from Sleep on Pin Change
• Selectable Oscillator Options:
    - INTRC: 4 MHz precision Internal oscillator
    - EXTRC: External low-cost RC oscillator
    - XT: Standard crystal/resonator
    - HS: High-speed crystal/resonator
        (PIC16F505 only)
    - LP: Power-saving, low-frequency crystal
    - EC: High-speed external clock input
        (PIC16F505 only)  (Continue ...)