Automotive driver-assist microcontrollers from Renesas feature direct RAM input interfaces

Combining 2 Mbytes (SH74504) /1.5Mbytes(SH74513) of embedded flash memory and 512 kbytes of on-chip SRAM, the devices allow high-speed processing of sensor data such as that captured by radar or onboard cameras. In addition, the ICs offer three direct RAM input interface (DRI) channels. These allow sensor data to be written direct to RAM without incurring any CPU overheard. The DRI feature supports direct parallel connection at up to 40 Mbps, from a 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). Also, a single channel I2C function is provided for camera settings.

Other on-chip peripheral functions include a parallel DAC controller (PDAC) circuit for controlling the D/A converter required by a driver-assist system employing radar, a parallel selector (PSEL) circuit for channel control of a high-speed A/D converter (ADC), a DRI circuit ideal for capturing data from a high-speed external AD converter, a TOU timer for controlling a brushless DC motor (BLDC) for mechanical radar scanning control, and a 65-channel ATU-III (Advanced Timer Unit III) multifunction timer unit suitable for timing control. These functions make it easier to realize a more compact system size at reduced cost

Fabricated using 90-nm process technology, 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 operation performance of 1.68 GFLOPS (giga [billion] floating-point operations per second) in single-precision mode. Hardware support for vector and sine or cosine arithmetic computations translates into high-speed calculation processing.

Five-channel CAN, and in the SH74504 two-channel FlexRay (version 2.1 compliant), the next generation standard automotive communication interface, are implemented as on-chip in-vehicle networking functions.

The SH74504 and SH74513 employ 17 × 17 mm BGA package that has a mounting area approximately 30% smaller than earlier LQFP product from Renesas Technology. 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 wider range of applications. The compact BGA package has a 0.8 mm pin pitch and an operating temperature range extending up to 125°C, making it a good fit for lightweight, compact, affordably priced in-vehicle systems.

A comprehensive range of compilers, flash development toolkits and the E10A-USB on-chip debugging emulator are available from Renesas Technology to aid system development. A variety of additional development tools are available from third-party vendors.