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SELECTING THE RIGHT MICROCONTROLLER UNIT

by Chad Gallun

Start ý Selection Process ý General Attributes ý MCU Resources ý Selection Criteria ý Memory ý System Cost Reduction ý Additional Hardware Requirements ý MCU Interrupts ý System Software ý Company Attributes ý Supplier Attributes ý Manufacturer Support ý Finalizing the Selection ý On Your Way ý Sources and PDF

SYSTEM COST REDUCTION

As the number and type of on-chip resources increase, the new modules help reduce overall system cost. Choosing a more expensive MCU that includes more system cost-saving features can lead to a lower application cost.

The following features help reduce cost by moving the components from the board into the MCU. Low-voltage reset adds system protection, COP guards against runaway applications, and high current drive on I/O pins helps (be wary of specs when comparing drive strengths (i.e., max drive versus tests/guaranteed)). Also, PLL (phase-locked loop) uses a lower cost, lower speed, crystal/resonator to generate high-speed internal clocks and also reduces emitted noise that can potentially reduce shielding requirements. Internal oscillators round out the picture for lower cost.

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