Meet MAX32690 EV Kit , powered by a 120 MHz ARM Cortex-M4F processor. Simply put, the board answers the following question: What if your evaluation board came with onboard real-time processing, wireless connectivity, and a TFT display all at the same time?
Figure1: Image of MAX32690 Evaluation board. (Source: Analog Devices).
Let’s dive deep into the heart of the board, the ARM Cortex-M4F CPU. As you might already know, ARM defines three major processor architecture profiles. They are:
- Cortex-A: Application processors.
- Cortex-R: Real-time safety-critical applications.
- Cortex-M: Microcontroller.
The three ARM processor profiles, A, R, and M, are relatively easy to remember because their names align with their primary design objectives.
Cortex-A is designed for high-performance applications such as single-board computers like Raspberry Pi or Mobile devices. Whereas the R series is designed for Real-time applications where quick response time is desired. For example, in Automobile controls, Industrial applications and Data storage devices like Hard Disks, etc. Finally, the Cortex-M series is used in microcontrollers and embedded systems where low power consumption and simplicity are important. So that explains why we are seeing a Cortex-M4 processor in our MAX32690 EV Kit.
What Does ARM Stand For?
It is also worth noting that ‘ARM’ does not represent the three processor profiles discussed above. ARM is now a famous architecture brand name. However, ARM stands for Advanced RISC Machine. RISC and CISC are two distinct CPU design philosophies that define how processors execute instructions. CISC stands for Complex Instruction Set Computer, and RISC for Reduced Instruction Set Computer.
How do M4 and M4F processors compare against the M3 processors?
● M3: general-purpose microcontroller processing
● M4: adds DSP-oriented instructions for signal-processing workloads
● M4F: adds a hardware single-precision FPU for floating-point calculations
Cortex-M4 adds DSP capabilities over Cortex-M3, while the Cortex-M4F variant adds a hardware single-precision FPU, as indicated by the letter ‘F’. Thus, floating-point calculations become much faster and easier with this microcontroller. On a Cortex-M4 without an FPU, the processor doesn’t have dedicated hardware for floating-point arithmetic calculations. The compiler therefore has to generate software routines to perform the floating-point operation, thus making it slower.
| Features | Cortex-M3 | Cortex-M4 | Cortex-M4F | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Instruction Set Architecture | Armv7-M | Armv7-M | Armv7-M | |||||||||
| Digital Signal Processing Extension | No | Yes | Yes | |||||||||
| Floating-Point Unit (FPU) | No | No | Yes, Single Precision | |||||||||
| FPU operation | Software emulated | Software emulated | Hardware, faster speed |
Table1: Comparison of various Cortex-M series processors (Data reproduced from: ARM)
Power Consumption
MAX32690 combines real-time processing capability with low power consumption (active-mode power of 85 µW/MHz at 1.1 V). Thus, the board combines strong processing power and low power consumption capabilities, ideal for IoT and portable and wearable wireless medical applications.
Communication Interfaces
Beyond Bluetooth 5.2 LE connectivity, the MAX32690 provides several high-speed interfaces for embedded applications including the following
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Multiple QSPI
- QSPI (Quad Serial Peripheral Interface) is a high-speed serial interface primarily used to communicate with external memory devices such as Flash memory. QSPI can transfer data over four data lines, allowing higher throughput than conventional single-bit SPI.
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UART
- UART (Universal Asynchronous Receiver/Transmitter) is one of the simplest methods of serial communication. It is commonly used for point-to-point communication between a microcontroller and devices such as computers, GPS modules, Bluetooth modules, or other microcontrollers.
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CAN 2.0B
- CAN (Controller Area Network) is designed for reliable communication between multiple controllers, particularly in electrically noisy environments. It is widely used in automobiles, industrial machinery, robots, battery systems, and EV charging equipment.
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I2C serial interfaces
- I2C (Inter-Integrated Circuit) is, however, a two-wire communication bus designed to connect a microcontroller to multiple peripheral devices. It can be used to interface peripherals such as ToF distance sensors, temperature sensors, RTCs, and display controllers.
What comes inside the box with MAX32690?
The MAX32690 EV Kit provides debugging support through a 10-pin SWD header, and it comes with a MAX32625PICO debugger shipped in the box. The PICO is connected to the MAX32690 using a ribbon cable.
Items included with the MAX32690 EV Kit:
- MAX32690 EV Kit
- MAX32625PICO Debugger with Cables
- Two USB Standard-A to Micro-B Cables
- Extra Shunts
- Bluetooth Hinged Whip Antenna
Note: The in-box MAX32625PICO, can be used as a standalone embedded development platform as well.
Figure2: Image showing all the items shipped along with the MAX32690 EV Kit.
With a basic understanding of the MAX32690 EV Kit and the Cortex-M4F processor at its heart, please feel free to take a closer look at how these features translate into practical embedded applications.
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