Introduction

Microchip offers two great 8-bit microcontroller families, the PIC and the AVR, and a designer often has to choose between them for a new project or a migration. Both are well supported, both are widely available, and both cover a similar range of applications, so the choice usually comes down to a few practical differences. This application note compares the two families on the core, the memory, the peripherals, the toolchain and the migration path, so an engineer can choose with confidence.

The Core

The PIC uses a compact RISC core with a small instruction set of 35 single-word instructions and a 200 nanosecond cycle, which is easy to learn and efficient for a control or an instrumentation task. The AVR uses a single-cycle RISC core with 32 general-purpose registers, which executes most instructions in one clock cycle and reaches about one MIPS per MHz. Both give a good performance for an 8-bit part, and the difference is small in practice; the PIC is often chosen for its simplicity and the AVR for its code density and its familiarity.

Performance and Power

Both cores are efficient and support low-power modes, so the power depends more on the peripheral usage and the clock than on the family. For a battery design, use the sleep and the idle modes of the chosen part and turn off the unused peripherals, and compare the current in each mode on the bench.

Memory and Peripherals

The PIC family offers the PIC16 at 14 KB of flash and the PIC18 at 32 KB, with on-chip EEPROM, and the AVR family offers the ATtiny at 8 KB, the ATmega328P at 32 KB and the ATmega2560 at 256 KB, also with on-chip EEPROM. Both families provide timers with PWM, a multi-channel ADC, a USART, an SPI port and an I2C interface, and the larger parts add more. The PIC18 and the PIC32 integrate USB, and the AVR parts cover a very wide I/O range. Count the peripherals and the I/O you need and compare.

Integrated USB and Communication

Where the design needs USB, the PIC18F4550 and the PIC32MX provide it on-chip, which is a practical advantage of the PIC family for a USB peripheral. The AVR family covers the rest with USART, SPI and I2C, and the choice follows the interface you need.

The Toolchain

Both families use the MPLAB environment and the XC compilers, so the same toolchain serves a PIC and an AVR design, which simplifies a mixed project and a team that works across the families. A large library of application notes and code examples is available for both, so the development is quick to start and well supported.

Code and Skills

Because the toolchain is shared, the skills carry across the families more than the register maps suggest. Keep the hardware abstraction layer clean, so the code that uses the peripherals is separate from the application logic, and a migration becomes easier.

Migration

A design can migrate between the families with care, because the peripherals and the register maps differ. Keep the hardware abstraction layer, re-check the timing and the clock tree, and test each peripheral on its own before the whole system. Replace a fixed delay with a timer where the timing matters, and re-check the loop timing after the port. This removes a whole class of migration bugs.

Choosing for a New Design

For a new design, choose the family that fits the interface and the tools your team already knows, because the practical cost of a new toolchain and a new code base is real. Both families are available from stock and supported by BeiLuo, so the supply is not a reason to choose one over the other.

Getting Help

If you send your workload, interface list, memory and package needs to our FAE team, we will compare a PIC and an AVR option and help you choose. BeiLuo holds mainstream Microchip MCUs in regional stock and ships them with an import declaration, a certificate of origin and a RoHS compliance file, and our engineers will review the choice with you before you commit to production.