IN Brief:
- The configurable logic block contains 128 basic logic elements and can execute digital functions without CPU intervention.
- Mixed-voltage I/O, analogue peripherals, timers, PWM, DMA, and serial interfaces are integrated alongside firmware-protection features.
- The family is available in 28-pin, 40-pin, and 48-pin packages, with a Curiosity Nano board supporting development.
Microchip Technology has moved its PIC18F-Q35 microcontroller family into wider distribution, combining an 8-bit embedded-control core with a configurable logic block that can execute digital functions independently of the processor.
Mouser announced availability on 3 August. The family integrates 128 basic logic elements, allowing designers to implement modest combinational and sequential functions on the device rather than adding a separate programmable-logic component for every timing, state, or interface task.
Each basic logic element contains a four-input look-up table and a flip-flop. The block can be configured through Microchip’s graphical CLB Synthesizer, which supports design entry, simulation, timing analysis, and hardware debugging inside the MPLAB Code Configurator environment.
The architecture is not intended to replace a large CPLD or FPGA. Its purpose is to absorb smaller pieces of glue logic, sequencing, waveform control, protocol handling, and signal conditioning that would otherwise consume processor time or add another component to the board.
Moving those functions into hardware can provide more predictable response than firmware where interrupt latency or software workload would make timing variable. The logic can also be loaded automatically during boot and continue operating while the CPU is halted, giving designers a route to deterministic behaviour without keeping the processor active.
The family includes mixed-voltage I/O, allowing peripherals operating in different logic domains to be connected without external level shifting in supported configurations. Its peripheral set also covers analogue-to-digital and digital-to-analogue conversion, comparators, timers, pulse-width modulation, DMA, I2C, SPI, and UART interfaces.
Microchip has added Programming and Debugging Interface Disable, which can block access through standard programming and debugging connections after deployment. That is intended to protect firmware and user data, although it places greater responsibility on the production process because incorrectly secured devices can become difficult to recover or analyse.
The devices are offered in 28-pin, 40-pin, and 48-pin variants with 16KB, 32KB, or 64KB of flash memory. Microchip is supporting development with the PIC18F56Q35 Curiosity Nano evaluation kit, which provides onboard programming and debugging and integrates with MPLAB X and MPLAB tools for Visual Studio Code.
For compact industrial and automotive designs, the combination could reduce external component count, board area, assembly operations, and supply-chain exposure. It may also shorten the signal path between control software and hardware logic, particularly where a small state machine or timing function sits close to analogue and communications peripherals.
Integration also concentrates dependency. A board using a discrete logic device may be easier to migrate to another microcontroller, while a design built around the PIC18F-Q35 logic fabric becomes more closely tied to Microchip’s architecture, configuration tools, and long-term device availability.
That trade-off matters in equipment expected to remain in production or service for many years. Designers will need to weigh component reduction against qualification, code maintenance, tool support, obsolescence planning, and the cost of reproducing the logic elsewhere if the product family changes.
The security functions require similar discipline. Disabling programming and debugging access can reduce the attack surface around production firmware, but it can also complicate servicing, failure analysis, and field recovery. Manufacturing controls must therefore confirm that the correct image, configuration, and protection state are applied before the interface is locked.
The strongest applications are likely to be systems that need deterministic local logic without the cost or complexity of a separate programmable device. Motor control, industrial interfaces, sensor nodes, secure peripherals, automotive subassemblies, and mixed-voltage control boards can all fit that requirement.
Wider distribution makes the family easier to prototype and specify, but the engineering value will come from disciplined partitioning. The configurable block earns its place when it removes a measurable timing, power, or component-count constraint, not when it is filled simply because spare logic is available.