PIC12F683: A brief Introduction

PIC12F683 is a 8-pin Flash based,  8bit RISC microcontroller from Microchip. This little PIC microcontroller offers up to 6 I/O pins (the remaining two are power supply pins). It needs no external oscillator, as it has an in-built oscillator with software selectable frequency from 8 MHz to 125 KHz. It also offers a feature that allows external signals to wake it upfrom the sleep state. Here are the various features as mentioned on the datasheet.


High-Performance RISC CPU:
• Only 35 instructions to learn: All single-cycle instructions except branches
• Operating speed:
 - DC – 20 MHz oscillator/clock input
 - DC – 200 ns instruction cycle
• Interrupt capability
• 8-level deep hardware stack
• Direct, Indirect and Relative Addressing modes

Special Microcontroller Features:
• Precision Internal Oscillator:
 - Factory calibrated to ±1%, typical
 - Software selectable frequency range of 8 MHz to 125 kHz
 - Software tunable
 - Two-Speed Start-up mode
 - Crystal fail detect for critical applications
 - Clock mode switching during operation for power savings
• Power-Saving Sleep mode
• Wide operating voltage range (2.0V-5.5V)
• Industrial and Extended temperature range
• Power-on Reset (POR)
• Power-up Timer (PWRT) and Oscillator Start-up Timer (OST)
• Brown-out Reset (BOR) with software control option
• Enhanced Low-Current Watchdog Timer (WDT) with on-chip oscillator (software selectable nominal 268 seconds with full prescaler) with software enable
• Multiplexed Master Clear with pull-up/input pin
• Programmable code protection
• High Endurance Flash/EEPROM cell:
 - 100,000 write Flash endurance
 - 1,000,000 write EEPROM endurance
 - Flash/Data EEPROM Retention: > 40 years

Peripheral Features:
• 6 I/O pins with individual direction control:
 - High current source/sink for direct LED drive
 - Interrupt-on-pin change
 - Individually programmable weak pull-ups
 - Ultra Low-Power Wake-up on GP0
• Analog Comparator module with:
 - One analog comparator
 - Programmable on-chip voltage reference (CVREF) module (% of VDD)
 - Comparator inputs and output externally accessible
• A/D Converter: 10-bit resolution and 4 channels
• Timer0: 8-bit timer/counter with 8-bit programmable prescaler
• Enhanced Timer1:
 - 16-bit timer/counter with prescaler
 - External Timer1 Gate (count enable)
 - Option to use OSC1 and OSC2 in LP mode as Timer1 oscillator if INTOSC mode selected
• Timer2: 8-bit timer/counter with 8-bit period register, prescaler and postscaler
• Capture, Compare, PWM module:
- 16-bit Capture, max resolution 12.5 ns
- Compare, max resolution 200 ns
- 10-bit PWM, max frequency 20 kHz
• In-Circuit Serial Programming™ (ICSP™) via two pins

The I/O port of PIC12F683 is called the GPIO (general purpose input/output file register), and the corresponding data direction register is TRISIO. It works mostly the same way as ports in other PIC microcontrollers. Setting a TRISIO bit (= 1) will make the corresponding GPIO pin an input, and clearing the TRISIO bit (= 0) will make it an output. One important thing to note is that GP3 is input only pin, and cannot be configured as an output.

PIC12F683 has a 13-bit program counter that can address up to 8K x 14 program memory, but only the first 2K x 14 (0000h-07FFh) is physically implemented. PIC12F683 also has 256 bytes of data EEPROM with an address range from 0h to FFh.
For details, read the datasheet.