The basic design principles of the four-stroke internal combustion engine has remained basically the same since patented in 1884. However, the engine control electronics have changed dramatically. The primary motivation is the need to meet legislative exhaust emission levels, provide competitive fuel economy, and meet customer quality expectations. For example, electronic fuel control is an enabler for meeting emissions and fuel economy goals. It also provides a variety of customer comfort features like cruise control, cold startability, fuel shutoff safety feature, and security lockout on startup.
Today’s vehicles have features such as gasoline direct injection (GDI), knock detection, catalytic converters, oxygen sensors, exhaust gas recirculation (EGR), evaporative emission control systems (canister purge and vent solenoid), misfire detection, and secondary air systems. Tomorrow’s vehicles will feature electronic throttle control (ETC), variable valve timing, cylinder deactivation, camless engines, in-cylinder combustion control, electronic stability, collision avoidance, and remote starting. These features will spawn new methods such as autocoding, autocalibration, generic operating systems, floating point math, DSP algorithms, and model-based control.
As the leader in the engine controller market, Freescale has developed the MPC500 family of embedded controllers. This family offers the high performance of a 56advanced peripherals, integrated Flash memory (up to 1MB) and fast static RAM (up to 36K) in a single silicon chip. The CPU contains an advanced floating point unit that is essential in the model-based strategies and autocoded control algorithms. The MPC500 family contains built-in calibration support with flexible overlay RAM. The QSMCM modules handle off-chip serial communications for UART and SPI functionality, while vehicle networking is supported with up to three TouCAN™ modules (CAN version 2.0b) and a J1850 interface. To meet the wide variety of performance and cost targets, the family offers many members that range from a low-end flashless device to a high-end 112 MIPS device with 1MB of integrated Flash.
Additional computing power is added to the MPC500 with the time processor unit (TPU3) (up to 3 on MPC565). These units have a 32-bit MicroRISC engine capable of processing 28 million instructions per second. The TPU runs independently and in parallel to the CPU. The TPU/CPU shares data through a dual-access RAM. Specifically designed for scheduling pulses in a circular system, the TPU is ideal for handling the angle domain operation. Each TPU contains 16 channels with independent match and capture hardware, multiple time bases, and a priority round-robin hardware scheduler to ensure that no task is locked out. The TPU is capable of running an engine even when the CPU has stopped running.
Freescale, as the leader in the automotive industry, continues to develop and improve engine controllers. Microprocessors of the future will contain features such as hundreds of megahertz, 100+ K-bytes of RAM, several megabytes of Flash (both on/off the main MCU), DSP support, caches (data and instruction), sophisticated branch predictors, large and powerful pipelines, and co-processors for timer system, communications, etc.
Block Diagram
应用手册:
http://www.freescale.com/files/shared/doc/selector_guide/SG2024.pdf
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