Renesas Electronics, has announced the availability of the RX71M Group as the new flagship product in the RX Family of 32-bit microcontrollers (MCUs). Developed for use in industrial equipment, the new series doubles the CPU operating frequency to 240 megahertz (MHz) from the 120 MHz of previous products and is available with up to 4 MB of on-chip flash memory.
Systems are more complex and larger in scale than previous versions while manufacturers are eager to adopt product development platforms to address increased development times and increased costs. On-chip flash memory MCUs are extensively used in midrange industrial equipment that are popularly priced in order to achieve a good balance between performance and system cost. M2M communication in industrial equipment has created demand for MCUs that are optimised for a range of performance levels, from sensor nodes operating at around 30 MHz to controllers operating at 200 MHz and above, and also for scalability in order to reduce the man-hours required for software and hardware development.
Recently, industrial customers are increasingly dispersing their system development efforts among multiple facilities and pursuing joint development arrangements with partners with strengths in specific technologies. This will result in reduced development costs of the new and advanced functions associated with transitioning to the IoT while increasing efficiencies and reducing development times. Such dispersed development and joint development approaches could bring risks to the customer’s own core technologies (such as important algorithms) such as leaks or unauthorised duplication. It has therefore become necessary to pursue development in a way that ensures one’s own software resources are protected.
Industrial equipment demands real-time performance since the sequence of processing steps, from data input to arithmetic processing to output of results must always finish within a set duration. When an MCU’s CPU operating speed is faster than the speed at which the flash memory can be accessed, dedicated high-speed on-chip SRAM can be added so that algorithms that require real-time processing can be run from the high-speed SRAM, but using dedicated SRAM in addition to the on-chip flash memory increases the cost. Furthermore, in cases where the on-chip memory capacity of previous flash microcontrollers was inadequate, it was necessary to add expensive high-speed SRAM or flash memory externally, increasing the BOM cost and the board mounting area.
Renesas developed the new RX71M group with precisely these needs in mind.
A total of 112 product versions are available with package pin counts ranging from 100 to 177 pins and on-chip flash memory capacities from 2 MB to 4 MB.
Key features of the new RX71M group:
1) Maximum operating frequency of RX Family lineup increased to 240 MHz, for a scalable range of products that contributes to reduced product development time and cost:
- With the appearance of the RX71M, the RX Family includes in addition to the RX100 Series operating at 32 MHz, the RX200 Series operating at 50 MHz, and the RX600 Series operating at 120 MHz, the new RX700 Series operating at 240 MHz, which is double the previous maximum operating frequency. This translates to performance of CoreMark/MHz = 4.4 @ 240MHz, among the best in the industry among flash microcontrollers.
- To smooth transitions among a wide range of products, the RX71M maintains backward compatibility with earlier RX Family products in aspects such as peripheral functions, development tools, and pin assignments
- The RXv2 core delivers approximately 1.3 times the performance of the earlier RXv1 core. It maintains complete code compatibility (backward compatibility) with the RXv1, ensuring easy software portability.
- Drivers with support for Firmware Integration Technology (FIT) make porting software between RX microcontrollers even easier. Development time and cost can be reduced by up to 50% when porting programme code between RX products. This helps customers in their efforts to develop products based on a common platform.
2) Expanded functionality for ensuring code data confidentiality and preventing unauthorised copying from the development stage onward, which is increasingly important as the move toward IoT brings more diverse communication interfaces and development becomes increasingly globalized:
- To support the increasing diversity of communication standards accompanying the trend toward IoT, the RX71M expands the list of supported communication interfaces beyond the earlier CAN and SPI to include SD Host Interface, USB High Speed (built into the PHY), and dual-channel Ethernet with IEEE 1588 support. This provides the connectivity with a wide variety of devices demanded in today’s industrial equipment.
- In response to the increased security risks accompanying the proliferation of communication standards, high-speed encryption functions (AES, DES, SHA, and RNG) are implemented in on-chip hardware. This provides robust protection against leaks of important data and communication data.
- Previous Renesas MCUs offered functionality to protect leaks of post-development code by preventing code stored in the on-chip flash memory from being read by external devices. The RX71M expands this coverage to the development stage with a trusted memory function that protects important algorithms from being leaked or copied without authorisation. The trusted memory function sets aside a special area of memory from which code cannot be read (copied) even by the internal modules of the microcontroller, such as the on-chip flash memory. This function prevents core software technology from being disclosed, even when development takes place at overseas facilities or is undertaken jointly with other companies.
3) Up to 45 percent reduction in BOM cost and double the performance of earlier products thanks to exclusive Renesas high-speed flash technology and large on-chip memory capacity
- High-speed flash memory employing the cutting-edge 40 nm flash process and capable of operating at 120 MHz, and the advanced fetch unit (AFU) incorporating exclusive cache-based memory control technology, achieve performance equivalent to no-wait access when operating at 240 MHz. Even if a cache miss occurs, the performance penalty is equivalent to only one cycle, so excellent real-time performance can be achieved even when using only the flash memory.
- The available on-chip memory configurations extend up to a maximum of 4 MB of flash memory, the largest capacity available in this class of product; 512 KB of parity checkable user RAM; and 32 KB of single error correction/double error detection ECC RAM. This makes it possible to do without external high-speed SRAM. The RX71M allows customers to utilize the on-chip memory to the full, realizing a reduction in BOM cost of as much as 45 percent.
Renesas intends to continue to develop and aggressively market MCUs combining advanced functionality and excellent performance for use in the industrial equipment and embedded networking devices forming the foundation of the continually expanding “smart society.”
Robust Development Ecosystem
For a quick development start, the RX71M MCU is supported by a robust development tool environment from both Renesas and third-party tool vendors that make up the RX ecosystem. Renesas provides a comprehensive development ecosystem for the RX Family, including e2 studio, a powerful Eclipse-based IDE, as well as compilers, debuggers, code generation tools, and flash programmers. In addition, the RX71M device is supported by the IAR Embedded Workbench for Renesas RX compiler and integrated development environment (IDE). RTOS and middleware is available from leading third-party companies such as Micrium, Segger, CMX, Express Logic, RoweBots, port GmbH and FreeRTOS.
Extensive software examples and drivers are provided by Renesas, including the Firmware Integration Technology (hereinafter “FIT”) Drivers. FIT is a completely new concept that emphasizes the simplification of embedding peripheral function module drivers and improves the portability between RX MCUs. Software examples and FIT drivers can be downloaded from the Renesas website.
