8051 vs. PIC: The Microcontroller Battle of the Century – Embedded Flakes

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In the world of embedded systems and microcontrollers, two titans have long stood at the forefront: the venerable 8051 and the versatile PIC (Peripheral Interface Controller). These microcontroller families have shaped the landscape of embedded design for decades, each bringing its unique strengths to the table. In this comprehensive analysis, we’ll dive deep into the intricacies of both architectures, exploring their histories, capabilities, and real-world applications to determine which might reign supreme in various scenarios.

Table of Contents

The 8051 microcontroller, first introduced by Intel in 1980, has become one of the most popular microcontrollers of all time. Its 8-bit architecture and robust design have stood the test of time, with numerous manufacturers continuing to produce variants with enhanced features.

Key milestones in 8051 evolution:

  • 1980: Original 8051 introduced by Intel
  • 1990s: Third-party manufacturers begin producing enhanced 8051 variants
  • 2000s: Introduction of high-speed 8051 cores and advanced peripherals

Microchip Technology’s PIC microcontrollers entered the scene in the mid-1970s, originally designed as a peripheral controller for the CP1600 CPU. The PIC architecture has since evolved into a diverse family of microcontrollers, ranging from 8-bit to 32-bit designs.

PIC evolution highlights:

  • 1975: First PIC device developed
  • 1985: General availability of PIC devices
  • Late 1990s: Introduction of PIC16 and PIC18 series
  • 2000s: Launch of 16-bit and 32-bit PIC microcontrollers

8051 Memory Structure:

  • Harvard architecture
  • Separate program and data memory
  • 64KB program memory
  • 256 bytes of internal RAM

PIC Memory Structure:

  • Modified Harvard architecture
  • Separate program and data memory
  • Program memory size varies by model (up to several MB in high-end devices)
  • Data memory size varies (from a few bytes to several KB)

8051 Instruction Set:

  • CISC (Complex Instruction Set Computing)
  • 255 instructions
  • Variable instruction length (1 to 3 bytes)

PIC Instruction Set:

  • RISC (Reduced Instruction Set Computing)
  • Fewer instructions (35 for PIC16, 75 for PIC18)
  • Fixed instruction length (typically 14 bits for PIC16, 16 bits for PIC18)

The 8051 and PIC families offer a wide range of clock speeds, depending on the specific model and manufacturer. However, we can make some general comparisons:

8051 Performance:

  • Traditional 8051 cores: 1-33 MHz
  • Enhanced 8051 cores: Up to 100 MHz or more

PIC Performance:

  • Low-end PICs: 4-20 MHz
  • High-performance PICs: Up to 200 MHz or more

It’s important to note that clock speed alone doesn’t tell the whole story. The RISC architecture of PICs often allows them to execute instructions more efficiently, potentially offering better performance at lower clock speeds.

8051 microcontrollers are typically programmed in C or Assembly. The robust ecosystem around the 8051 has led to the development of numerous IDEs and toolchains.

Sample 8051 C code for blinking an LED:

#include 
#include 

void delay(unsigned int count)
{
    unsigned int i;
    for(i=0;i