Hardware Architecture & SoCs Topics
Covers chip design, System-on-Chip (SoC) architecture, custom silicon strategies, hardware accelerators, IP development, and the integration of silicon design with software ecosystems.
Electrical Fundamentals for Firmware Developers
Core electrical engineering concepts that firmware developers need to understand and apply when working closely with hardware. Topics include voltage and current behavior, power budgeting and sequencing, ground and reference considerations, power distribution and regulators, decoupling and bypass strategies, impedance and parasitic effects, signal integrity including reflections and crosstalk, thermal considerations, input and output drive capability, level shifting, analog to digital converter and digital to analog converter considerations, electromagnetic interference and electromagnetic compatibility concerns, and practical mitigations such as filtering, shielding, and layout best practices. Candidates should be able to read electrical specifications from data sheets, choose appropriate measurement tools such as oscilloscopes and multimeters, and know when to consult electrical engineers for layout and compliance issues.
Hardware Platforms and Development Boards
Knowledge of microcontroller and development board ecosystems used for embedded projects. Candidates should be able to describe experience with families of controllers such as ARM Cortex M series and commonly used vendor lines, selecting appropriate development boards such as Arduino or vendor system on modules, and the trade offs between different platforms with respect to memory, peripherals, power, and cost. This includes familiarity with cross compilation toolchains and board support packages, flashing and boot procedures, bring up workflows, debugging interfaces and adapters, vendor SDKs and drivers, and practical concerns such as pin multiplexing and power rails. Interviewers may probe ability to choose a board for a particular constraint set and to explain environment setup and validation steps.
Signal Integrity and Hardware Interaction
Fundamental electrical and physical interface concepts that affect how firmware and hardware interact. Topics include pull up and pull down resistor usage, input debouncing strategies, signal noise and crosstalk, level shifting, grounding and return paths, impedance mismatches, and analog to digital sampling issues. Candidates should also be able to explain how firmware design mitigates signal problems through filtering, sampling choices, hysteresis, retry and validation logic, and how to collaborate with hardware engineers to diagnose and resolve signal integrity problems.
Sensor Integration and Data Acquisition
Designing and implementing reliable sensor interfaces and data acquisition pipelines for embedded systems. Topics include selecting sensors and front end components based on accuracy, range, noise, sampling rate, and power; interfacing sensors using serial peripheral interface, inter integrated circuit, or analog inputs; understanding analog to digital converter characteristics such as resolution, sampling rate, reference voltage, input impedance, and quantization noise. Covers sampling strategies including periodic sampling, event driven sampling, and duty cycling; anti aliasing and sample rate selection; hardware and digital filtering techniques including moving average, finite impulse response and infinite impulse response filters; calibration methods for offset, scale, and temperature compensation; driver and firmware design patterns including interrupt driven and direct memory access based acquisition, buffering strategies such as ring buffers and queues, timestamping, and handling backpressure. Also includes trade offs among latency, power, memory, and accuracy, and approaches for validating sensor data and handling degraded sensor conditions.
Hardware Simulation and Protocol Implementation
Building software models and test harnesses that emulate hardware behavior and implementing robust communication protocol drivers. Topics include creating unit level hardware mocks, instruction set or cycle accurate simulation, co simulation with hardware description language models, and reproducible test benches for timing sensitive code. Protocol implementation covers framing, byte and bit level timing, error detection and correction such as checksums and cyclic redundancy checks, bus arbitration and collision handling, clock stretching, and retry and timeout strategies. Focus on handling edge cases such as partial transfers, bus contention, jitter, and unexpected resets by modeling timing and validating with hardware in the loop. Also covers driver layering, abstractions for testability, conformance and fuzz testing, and integrating simulation into verification and regression pipelines.
Hardware and Software Integration
Design and implementation patterns for mapping software to physical hardware capabilities. Topics include microcontroller and system on chip capabilities, memory and peripheral access models, register and memory mapped I O, general purpose input output, sensor and actuator interfacing, serial and parallel peripheral protocols, direct memory access, timing constraints, interrupt versus polling trade offs, device driver design, hardware abstraction layers, power and thermal considerations, and how to make software choices that respect hardware limits while meeting latency and reliability requirements.