Freescale MCUs simplify car wiring system, cut vehicle weight

Freescale MCUs simplify car wiring system, cut vehicle weight

The second-heaviest component of a modern car - after the engine - is the cable loom. New applications raise the demand for more bandwidth, more connectivity - and even more wires within the car. With a new range of microcontrollers for body applications, Freescale promises to enable designers to reduce this weight. The approach: higher functional integration will reduce the need to send signals across the body of the car.
By eeNews Europe


The growing number of electronic control units (ECUs) in cars causes the complexity of the wiring system to grow accordingly. In an average passenger car, the infrastructure for data and signal transport embraces copper wires with a total length of several kilometres. The weight of these cable looms easily exceeds 70 kilograms, the weight of an adult man. Weight, in turn translates into fuel consumption and cost. The weight of these wiring systems can significantly be reduced if more functions are integrated into less ECUs. For years, major OEMs are calling for a reduction in the ECU count. A "domain controller" could assume the functionality of several disperse single-function ECUs, effectively reducing the overall weight of the vehicle and along with the weight the fuel consumption.

Besides the demand for more "green" cars, there is a rising demand for functional safety, defined by the ISO26262 standard. This demand includes the design of safety-relevant functions such as exterior light and windscreen wipers.

Freescale has customized the new Qorivva MPC5748G and S12 MagniV S12VL/S12ZVC MCUs to meet this demand. They complement the central Qorivva Controller which with centralized functions for data privacy and security, intelligent power management and ASIL support for functional safety assumes the functions of a gate keeper for the internal data network. The S12 MagniV satellite nodes are equipped with an integrated power supply on their mixed-signal MCU. The extreme degree of integration offered by these components can significantly contribute to simplify the power and data network in the vehicle. Up to 10 kilograms less weight is what Freescale promises in this context, yielding better efficiency in the manufacturing process and up to 30 % smaller PCBs.

The Qorivva MPC5748G MCU is a single-chip solution for next-generation central body control and gateway applications. It combines a high level of integration with low-power management modes, support for functional safety and robust security features.

Fig 1: Qorivva MPC5748G Block diagram. For higher resolution click here.

The MPC5748G MCU provides one of the most diverse sets of networking communications peripherals on the market, with support for Ethernet with Audio Video Bridging (AVB), FlexRay, Media Local Bus (MLB), USB, CAN FD (Flexible Data Rate) and up to 18 LIN controllers. High performance through a multicore architecture help ensure efficient transfer of data and eliminate communication bottlenecks.

Central body control modules spend significant portions of time in a low-power monitoring state. The MPC5748G features a low-power unit (LPU) mode that allows for increased functionality in a lower-power state, cutting peak current consumption for cyclic wakeup use cases by nearly 30 percent compared to previous-generation devices. In addition, inclusion of analog comparators that operate out of standby mode and pretended networking help support next-generation power budget requirements.

The MPC5748G is a Freescale SafeAssure functional safety solution, defined and developed from the ground up to address the ISO 26262 standard. Built-in safety functions such as self testing and end-to-end error correction coding (ECC), comprehensive auto safety software including AUTOSAR OS and MCAL drivers and extensive safety documentation help target the use of the device for ASIL B.

The MPC5748G offers a hardware security module (HSM) for data protection and ensures secure communication and flash updates through AES cryptographic algorithms, secure memory and secure boot capabilities.

Increasing the intelligence of CAN termination nodes or LIN nodes using the highly integrated S12 MagniV S12ZVL/S12ZVC MCUs will help automotive OEMs optimize their total body networking systems. The S12ZVL/S12ZVC devices allow designers to achieve the smallest possible CAN termination nodes (using S12ZVC) or LIN nodes (using S12ZVL) and help reduce printed circuit board sizes by as much as 30 percent. Car systems can connect high-voltage signals and power supplies directly to the S12 MagniV MCU, helping save additional discrete components, increasing system quality and reducing system design and manufacturing complexity.

Fig. 2: Block diagram of the S12 ZVC product family

The S12 MagniV portfolio enables body electronics platform design scalability across multiple applications, with CAN and LIN connectivity options and a range of package options between 32 and 64 pins.

The S12 MagniV S12ZVL/S12ZVC MCUs are the first devices from the Freescale 16-bit automotive MCU portfolio included in Freescale’s SafeAssure functional safety program. They have been defined and developed from the ground up to address the ISO 26262 standard.

The devices will be available in sample quantities in the Q2/13; high-volume availability is scheduled for Q2/2014.