Renesas to Release MCUs with On-Chip Flash Memory, SRAM for Auto Driver-Assist System Control

November 17, 2008 // Published as a news service by IHS

Sample shipments will begin in February 2009 in Japan.

The SH74504 and SH74513 are built around the SH-4A central processing unit (CPU) core. Fabricated using 90 nanometer (nm) process technology, they operate at 240 MHz.

According to Renesas, they provide ample memory capacity, combining 2 MB for the SH74504, 1.5 MB for the SH74513 of embedded flash memory and 512 KB of on-chip static random access memory (SRAM).

This provides support for driver-assist systems offering enhanced performance by enabling high-speed processing of the large volumes of sensor data required by obstacle detection and collision avoidance applications, Renesas said.

These MCUs offer on-chip in-vehicle networking capability with five-channel controller area network (CAN), and in the SH74504 two-channel FlexRay, a communication protocol for next-generation vehicle control applications.

The features of the SH74504 and SH74513 are as follows:

• 240 MHz high-speed operation. The SH74504 and SH74513 are built around the SH-4A CPU core, which has been used in applications such as car navigation systems.

  Their maximum operating frequency of 240 MHz is the fastest in the industry for MCUs with embedded flash memory, allowing them to achieve processing performance of 432 million instructions per second (MIPS), Renesas said.

  This is 1.5 times faster and approximately 2.6 times the operating performance of the earlier M32192, making it possible to build driver-assist systems with even better performance, according to the company.

• On-chip flash memory and SRAM operating at temperatures up to 125 degrees Celsius. The SH74504 and SH74513 are fabricated using 90 nm process technology and have up to 2 MB of on-chip flash memory, enabling them to store large programs.

  They operate at a temperature range of -40 degrees Celsius to +125 degrees Celsius.This enables them to tolerate the high-temperature environment demanded by applications such as driver-assist systems, Renesas said.

  The SH74504 and SH74513 also have 512 KB of on-chip SRAM, approximately three times the capacity of comparable earlier products. This enables them to handle larger amounts of data, such as milliwave radar data or video data from onboard cameras, and to deliver enhanced processing performance, according to the company.

• Support for in-vehicle network communication, including on-chip FlexRay functionality. In a driver-assist system, a sensor fusion electronic control unit (ECU) controls information detected by sensor ECUs, from milliwave radar and camera sensors, via a CAN network.

  The SH74504 and SH74513 increase the number of CAN channels from the two of comparable earlier products to five to accommodate the increasing number of sensor ECUs and actuator ECUs in today's high-performance driver-assist systems.

  Renesas said the volume of data transferred is expected to increase rapidly due to coordinated control among in-vehicle systems, and it is possible that the current CAN communication speed will become inadequate. To handle this, the SH74504 implements two FlexRay channels conforming to the next-generation basic standard.

  FlexRay 2.1 protocol has a higher communication speed than CAN networks and allows for greater flexibility in the amount data being transmitted; with two FlexRay channels, the SH74504 allows for redundancy, which is needed in safety critical applications, Renesas said.

• Ball-grid array (BGA) package targeting a smaller system form factor. The SH74504 and SH74513 employ a 17 millimeter by 17 millimeter BGA package that has a mounting area approximately 30% smaller than earlier low-profile quad flat package (LQFP) products from Renesas.

  This package has multiplexed pins that can be assigned to more than one function. The number of functions per pin has been increased to six from four in comparable earlier products to provide support for a range of applications. The BGA package has a 0.8 millimeter pin pitch and an operating temperature range extending up to 125 degrees Celsius.

Both the SH74504 and SH74513 have an on-chip floating-point processing unit (FPU) with a maximum operating frequency of 240 MHz. The FPU supports single- and double-precision calculations and achieves a maximum operating performance of 1.68 giga (billion) floating-point operations per second (GFLOPS) in single-precision mode. Hardware support for vector and sine or cosine arithmetic computations translates into high-speed calculation processing, Renesas said.

Both MCUs consume only 1.5 watts (W) of power when they operate at 240 MHz. In addition, the SH74504 and SH74513 integrate the following peripheral functions required by driver-assist systems:

• On-chip functions for onboard camera control. The three-channel direct random access memory (RAM) input interface (DRI) function supports direct parallel connection at up to 40 Mbps from a complementary metal-oxide semiconductor (CMOS) camera with a maximum of wide video graphics array (WVGA) resolution to on-chip SRAM as a camera interface for the lane departure warning system (LWDS), and a one-channel inter-integrated circuit (I2C) function is provided for camera settings. The 512 B of on-chip SRAM can store the data for an entire photo.

• On-chip functions for vehicle milliwave systems. The on-chip peripheral functions include a parallel digital-to-analog converter (DAC) controller (PDAC) circuit for controlling the DAC required by a driver-assist system employing milliwave radar, a parallel selector (PSEL) circuit for channel control of a high-speed analog-to-digital converter (ADC), a DRI circuit for capturing data from a high-speed external ADC, a time-of-use (TOU) timer for controlling a brushless direct current motor (BLDC) for mechanical milliwave scanning control and a 65-channel advanced timer unit III (ATU-IIIS) multifunction timer unit suitable for timing control.

• On-chip port-to-port communication function for multi-CPU configurations.

The SH74504 and SH74513 also incorporate the following communications functions:

• A DRI and direct RAM output interface (DRO) to minimize performance drag on the MCU's CPU caused by CPU-to-CPU communications functions.
• A bus controller that supports selection of the optimal data bus width (8 b, 16 b, 32 b) when an external bus is used.
• Serial communication interfaces (SCIFs) with first in, first out (FIFO).

There is also an on-chip direct memory access controller (DMAC) supporting data transfer to external bus areas to enable management of the communication functions.

Compilers, the E10A- universal serial bus (USB) on-chip debugging emulator, flash development toolkits and starter kits manufactured by Renesas Technology are available for use in system development. A variety of additional development tools are available from third-party vendors.

Source: Renesas Technology Corp.