Microchip Prioritizes Customizable Logic in New 8-bit MCUs
Outfitted with a configurable logic block module, the new MCUs integrate customizable logic to reduce BOM and improve performance.
As microcontrollers (MCUs) become more central to the operation of IoT devices, designers need low-power, high-performance MCUs that don't increase system complexity.
To answer this call, Microchip recently announced a new family of devices that integrates customizable logic directly into the MCU. What might this integration mean for the future of embedded systems?
Microchip claims that its new configurable logic block (CLB) module enables customizable hardware solutions and may even eliminate the need for external logic components.
New 8-bit MCUs Integrate Configurable Logic Block
The new PIC16F13145 MCU family introduces a configurable logic block (CLB) peripheral. The CLB consists of 32 individual logic elements, each employing a look-up table (LUT)- based design. This feature enables designers to create hardware-based, custom combinational logic functions directly within the MCU, optimizing the speed and response time of embedded control systems. This integration eliminates the need for external logic components, thereby reducing bill of materials (BOM) costs and power consumption.
A diagram of a basic logic element in the PIC16F13145.
Another important feature of the CLB is its independence from the central processing unit's (CPU) clock speed. This allows the CLB to make logical decisions while the CPU is in sleep mode, further reducing power consumption and software reliance.
The MCU family (datasheet linked) is available in various package sizes, including 8-, 14-, and 20-pin configurations, and offers up to 14 KB of program flash memory and up to 1 KB of RAM. This goes along with an integrated 10-bit ADC with computation (ADCC) capable of up to 100 ksps, an 8-bit DAC, and two fast comparators with a 50-ns response time. These features are complemented by a range of peripherals for timing control and serial communications, including SMBus compatibility.
Understanding Customizable Logic
Customizable logic allows hardware-based logic functions to be implemented directly within the MCU. Traditionally, such functions required external components like programmable logic devices (PLDs) or additional microcontrollers. However, with customizable logic, these functions are integrated into the MCU itself, simplifying design, reducing system footprint, and minimizing system latency.
At the heart of customizable logic in MCUs like Microchip’s new family is the configurable logic block (CLB). A CLB generally consists of multiple logic elements, each of which can be individually programmed to perform various logic functions. These logic elements are commonly based on LUTs, which can be configured to implement complex combinational logic or simple logic gates like AND, OR, and XOR. By programming these LUTs, engineers can create custom logic circuits that operate independently of the MCU's CPU.
Configurable logic blocks are software-defined hardware. (Click to enlarge.)
One key advantage of integrating customizable logic into MCUs is that it enhances real-time performance. Since these logic blocks operate independently of the CPU, they can make quick logical decisions, effectively reducing system latency. This is particularly advantageous in applications requiring rapid response times, such as motor control, industrial automation, or real-time data processing.
Another significant benefit is power efficiency. Customizable logic can often operate in low-power or sleep modes, making logical decisions without waking the CPU. This feature is invaluable in battery-powered or energy-sensitive applications where conserving power is crucial.
Emblazoning MCUs in Embedded Designs
By embedding customizable logic into its family of MCUs, Microchip is offering designers new ways to get more performance and efficiency out of their embedded designs. Without the need for extra components, engineers can now create dedicated logic blocks to accelerate their product’s unique tasks, helping them balance the cost-performance tradeoff.
All images used courtesy of Microchip.
Potentially interesting, but I have to wonder how much of your 1.5k program memory is typically left after you finish setting the rather large number of configuration bits associated with all the onboard peripherals.