RX700 MCU offers 240-MHz, run-from-flash operation
The RX71M Group is 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 MHz from the 120 MHz of previous products and is available with up to 4 MB of on-chip flash memory. The flash memory is built in Renesas’ own MONOS, 40-nm process which achieves 8-nsec access times, four times faster than alternative technologies, and with long endurance and reliability.
On-chip flash memory MCUs, Renesas notes, are extensively used in midrange industrial equipment 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.
Renesas finds that 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. Software resources must be protected.
Industrial equipment demands real-time performance. 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. 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 these needs in mind.
A total of 112 product versions is 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) simplify porting software between RX microcontrollers. Development time and cost can be reduced by up to 50% when porting program code between RX products.
2) Expanded functionality for ensuring code data confidentiality and preventing unauthorised copying from the development stage onward.
– 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.
– 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.
– 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% reduction in BOM cost and double the performance of earlier products with Renesas’ high-speed flash technology and large on-chip memory capacity
– High-speed flash memory 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 MCU is supported by a 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.
Software examples and drivers are provided by Renesas, including the Firmware Integration Technology ("FIT") Drivers. FIT is a 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.
Renesas; www.renesas.eu
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