Embedded Systems & Firmware

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Standards-compliant real-time firmware for mission-critical control and power-electronic platforms.

Embedded software sits at the intersection of real-time control, hardware integration, safety compliance, and system architecture. At MarSum Solutions, we treat firmware development as an integral engineering discipline — embedded from the first architecture draft.

Our approach ensures that every embedded implementation meets its control targets, timing constraints, diagnostic needs, and certification requirements. Whether it’s powering a multi-kilowatt drive system, managing safety functions in an industrial inverter, or executing estimator algorithms on a DSP, we build firmware that works predictably — and safely.

We design embedded software stacks that are deterministic, modular, and maintainable — supporting real-time constraints without sacrificing clarity or traceability.

Architectural Elements We Implement:

• Bare-metal or RTOS-based frameworks, depending on system complexity
• Interrupt-driven or scheduler-based event loops
• Time-sliced task execution and prioritization strategies
• Deterministic control ISR integration (e.g., PWM trigger, ADC sync)
• Peripheral abstraction layers for SPI, CAN, UART, I2C, GPIO
• Bootloader and firmware update support (over CAN, UART, SD)
• State machines for fault handling, power sequencing, and control modes (Stateflow or hand-coded)
• ISR latency consistently held under 2 µs for control loops on DSP targets
   

Platform Experience:

• ARM Cortex-M (STM32, NXP LPC/IMXRT, TI MSPM0)
• ARM Cortex-R (TI Hercules RM4x / TMS570 series)
• TI C2000 series DSPs
• Microchip dsPIC
• Altera/Intel MAX10, Lattice XP2/ECP5/MachXO3D for embedded FPGA control logic
• Mixed MCU + FPGA co-design for deterministic and parallel execution

We implement and optimize control algorithms for embedded targets — translating model-based designs into efficient, testable, real-time firmware.

Key Techniques:

• Fixed-point conversion of Simulink/Matlab controller blocks
• Assembly-level optimization of time-critical paths
• Interrupt nesting, priority tuning, and jitter control
• Digital filter implementation (FIR/IIR) for current/voltage loops, position feedback
• Cordic and LUT-based trigonometric evaluations for motor control
• Support for control modes including:
  • FOC (Field Oriented Control)
  • DTC (Direct Torque Control)
  • SVPWM (Space-Vector PWM)-based modulation
  • Hysteretic and peak-current-mode control (PCM)
• <100 ns ISR jitter consistently achieved on TI C2000 DSPs
   

Auto-Code Integration:

• MATLAB® Embedded Coder™, Simulink Coder™, HDL Coder™
• Manual refactoring for memory, stack, and timing constraints
• Hybrid auto-code + hand-code workflows to blend efficiency and clarity
• Fully traceable implementation from model to C source

We design embedded systems that communicate reliably — even in EMI-prone industrial and automotive environments.

Interfaces and Protocols:

• CAN 2.0 / CAN-FD, CANopen, RS-485, Modbus, LIN, Ethernet, SPI, UART
• Safety comms with CRC checks, watchdog timers, and heartbeat validation
• DMA-based data handling for non-blocking performance
• Custom protocol stacks and bridging logic for hybrid bus systems
• Flash memory handling and EEPROM emulation for persistent parameters
   

Sensor & Peripheral Integration:

• Real-time logging, trace capture, and boot-time diagnostics
• Shunts, Hall sensors, NTCs, encoders, accelerometers
• High-resolution ADC with digital filter chains

We build firmware that supports system-level functional safety, fault handling, and standards compliance.

Safety Features and Standards:

• Compliance with MISRA C, ISO 26262, IEC/UL 60730-1 Annex H (Class B), IEC/EN 60335-1/-2
• Safe state entry, brownout, and power-fail recovery logic
• Memory CRC, stack overflow detection, and watchdog supervision
• Function isolation and fail-silent mode support
• Diagnostic coverage metrics and structured fault categorization
• Software FMEA and safety-goal traceability
• ASIL B–D compliant designs with freedom-from-interference partitioning
• Release planning with versioning, digital signatures, and rollback

Embedded firmware is only as good as its test strategy. We integrate simulation, bench testing, and in-system evaluation early in the cycle.

Verification Methods:

• Unit testing and coverage analysis (with embedded test harnesses)
• Static analysis using PC-lint++ or Coverity
• HIL and SIL integration using NI VeriStand, Speedgoat Simulink Real-Time, or dSPACE setups
• Processor-in-the-loop (PIL) for benchmarking control ISR paths
• Fault injection: sensor dropout, communication timeout, overflow, invalid state simulation
• Continuous integration with regression tests and test coverage tracking
• Runtime loggers and trace tools for in-field issue replication
• End-of-line fixture support and diagnostic pin mapping