i.MX RT Crossover MCUs

A crossover MCU blends the design simplicity of a microcontroller with the performance of an applications processor. Using a microcontroller class CPU core such as an Arm Cortex-M or Cortex-M33 running at speeds of up to 1GHz, users can benefit from being able to run bare-metal or with a real-time operating system (RTOS).

Via the combination of fast code execution from internal tightly coupled memories (TCM) and the ability to directly access peripherals and interrupts without additional operating system overhead. The i.MX RT crossover parts can simultaneously run a sophisticated RTOS such as Zephyr while maintaining real-time processor and IO requirements. Users benefit from being able to get the “best of both worlds”.

Cost

Moving the flash memory external to the part means that customers can select from a large variety of components in the marketplace that are suited to their application requirements. Users get the flexibility of sourcing flash from multiple vendors while being able to tailor capacity to application requirements and cost targets.

Boot Flexibility

The i.MX RT Crossover MCUs can execute in place (XIP) from an external flash or use the external flash as storage to copy code into RAM. It is even possible to boot from media such as an SD card. The FlexSPI interface allows for a variety of devices and interfaces such as single, quad, or octal DDR modes. There are also options for adding additional boot recovery sources to ensure that products always can reliably boot and implement robust OTA update mechanisms.

Speed

The i.MX RT crossover MCUs have cache memories and memory protection. This means executing from external flash does not mean a drop in performance.

For devices such as the RT10xx, there is a traditional external memory controller (EMC) for adding commodity SDRAM. The EVK’s for the RT1020, RT1040, RT1050, RT1060 and RT1170 demonstrates how to add memory via the EMC.

It is also possible to add extra memory via the FlexSPI ports. There are options for PSRAM that have a quad or Octal DDR interface. You can see an example of this on the RT685 and RT595 EVKs. It is even possible to add memory with a simple 4-bit interface for simpler PCB designs.

The i.MX RT family is supported by all the major RTOS’s such as FreeRTOS and Zephyr. The MCUXpresso SDK includes several FreeRTOS examples. NXP actively contributes to the Zephyr community and is a founding/platinum member. All the i.MX RT EVKs have board support packages in the Zephyr source tree, which are actively maintained.

The i.MX RT crossover MCUs implement all the typical peripherals that you would come to expect, such as CAN, SPI, I²C and Ethernet. Some of the i.MX RT family have peripheral features that are unique. Some of the parts have MIPI display interfaces with 2.5D graphics acceleration for more sophisticated HMI interfaces. The i.MX RT600 is an audio focused part with large on-chip SRAM, supporting up to 8 digital microphones, a large number of I2S interfaces and even has a 600MHz HiFi4 DSP co-processor. The RT10xx implements two high-speed USB ports for interesting USB use cases. Another unique peripheral is the internal peripheral crossbar (XBAR). It enables sophisticated chaining of peripheral functions to offload complex IO operations with minimal CPU intervention.

The i.MX RT crossover MCUs support the latest interface standards with the RT500, RT600 and RT1180 implementing a MIPI I3C interface. The FlexIO can be used to create various unique serial or parallel interfaces, like, for example, a camera interface or display interface.