Brief Analysis of the Design of Digital Virtual Instruments for Automobiles Based on MB86R01

With the huge demand for intelligence in the automotive, communications, information appliances, medical, military and other industries, embedded software and systems are developing rapidly. Microprocessors have evolved from 8-bit to 16-bit, 32-bit and even 64-bit, from supporting a single variety of CPU chips to supporting multiple varieties, from a single core to providing other functional modules in addition to the core. Moreover, with the continuous innovation of hardware technology, the processing power of the hardware platform has been continuously enhanced, and the cost has been continuously reduced. Embedded software has become a key and driving technology for the digital transformation and intelligent value-added of products. Therefore, developing a hardware platform that integrates embedded control, high-speed data acquisition and network communication, and provides a friendly human-machine interface and multiple bus interfaces is of great significance to improving the reliability and networking flexibility of embedded systems.

Based on this, the MB86R01 chip introduced in this article integrates the ARM926EJ-S core, 2D/3D display, vehicle communication functions, and various application interfaces into a single chip, with high integration and strong intelligence. It also supports program protection functions to prevent illegal reading and tampering.

1 Working mechanism of MB86R01

MB86R01 chip is a 16/32-bit RISC embedded microprocessor based on ARM926EJ-S core launched by Fujitsu, mainly for car navigation and instrument panel. ARM926EJ-S processor has complete memory management, high performance, low grain size and low power consumption and other important multi-task processor applications; supports 32-bit ARM and 16-bit Thumb instruction sets; supports ARM debugging system and includes logic to support hardware and software debugging; has a cached Harvard bus system and provides a complete high-performance processor subsystem, including:

(1) An ARM926EJ-S fixed-point (integer) core;

(2) a memory management unit (MMU);

(3) Separate instruction and data AMBA AHB bus interfaces;

(4) Separate instruction and data TCM interfaces.

The internal structure of MB86R01 is relatively complex, mainly including ARM9 core, graphics display controller, USB multimedia system interface, CAN controller, and hard disk interface IDE66 (Parallel-ATA/ATA PI-5), etc. The internal structure of MB86R01 is shown in Figure 1.

MB86R01 provides a very complete set of general system peripherals and minimizes the consumption of the entire system. It also has many commonly used modules, so there is no need to add additional configuration equipment. The functions integrated on the chip mainly include the following aspects:

◇Using 90nm process;

◇The operating frequency of the internal memory controller is 320MHz;

◇Display resolution: Industry standard display resolution, from 320*240 to 1024*768;

◇With EMT9 and JTAG ICE interface;

◇ Built-in external DDR2 (frequency: 166MHz/dual edge: 333MHz) and memory interface to support high-speed operation;

◇With parallel Flash/SRAM host interface;

◇With parallel ATA interface;

◇SD card interface;

◇CAN controller interface;

◇MediaLB interface;

◇USB2.0 multimedia system interface;

◇I2C interface;

◇I2S interface;

◇SPI interface:

◇ADC interface;

◇PWM interface;

◇GPIO interface;

◇UART interface;

◇Temperature range is -45～+85℃;

◇Power loss: 1.5W;

◇Package: molecular compound plastic ball grid array 484 pins (PBGA484);

◇It has an extended external bus to support software development and hardware debugging.

1.1 Graphics Display Controller (GDC)

The image display controller MB86296 integrated in MB 86R01 is 32-bit and has multiple human-machine interfaces. It combines multiple functions required by the automotive environment. Its main function is to control the LCD panel when displaying rich image content. Other functions include viewpoint navigation, real-time display of analog measuring instruments and two brushes, and other information display that does not put too much pressure on the main CPU. The specific functions integrated inside are introduced as follows:

(1) It has a geometry engine that can achieve precise digital graphics processing through floating-point operations.

(2) It has RGB/YUV dual video display and output, and can perform video capture. It can store digital video data in DVD and other graphic storage devices. The brightness, saturation and contrast of the video input can be controlled by programming.

(3) It has a dual display function, which can display videos and images on the same screen to provide high-definition maps or images.

(4) Supports 6-layer overlay/alpha blending, and the 6-layer display supports 4 different color palettes, each palette provides 256 colors. All layers provide 24 or 16-bit resolution direct color or 8-bit resolution indirect color. And the display resolution ranges from 320*240 to 1024*768.

(5) It has a 2D/3D drawing engine and is compatible with 2D/3D graphics cards (166MHz). In addition to regular 3D drawing functions such as shadows, textures, and texture mapping, the hardware also supports "bold lines", "dotted lines", and "diagonal lines" that are most suitable for maps. When used in combination with the graphic anti-aliasing function, it can draw smooth and beautiful straight lines. It can also draw according to depth and simply express intersections and three-dimensional intersections.

(6) Provides 200MHz to 400MHz display clock frequency, the controller is rated at 1.8V, 500mA and 3.3V, 100mA, and is compatible with Fujitsu

Some graphic display controller ICs are compatible, do not require external additional logic circuits, and can be used for different host CPU buses.

(7) Support texture mapping (video material), with maximum mapping unit up to 4096*4096.

The internal structure of MB86296 is shown in Figure 2.

1.2 Multiple peripheral interfaces for built-in vehicle communication/media network

In the automotive electronics sector, the integration of vehicle control systems and infotainment systems is accelerating. This device has built-in CAN and MediaLB as vehicle communication interfaces, USB as multimedia interfaces, IDE66 (Parallel-ATA/ATAPI-5) as hard disk interfaces, and I2S as audio interfaces, and has a variety of peripheral interfaces. This product can meet all needs from vehicle communication control to multimedia processing with just a single chip.

1.3 Support program protection function

In recent years, the digitization of car dashboards has been accelerating, and with it there has been a trend to externalize the Flash-ROM that stores basic software. Therefore, measures need to be taken to prevent illegal reading and tampering of ROM code. MB86R01 meets this demand and supports a program protection function that allows programs to be encrypted using a self-defined key.

2 With operating system application

MB86R01 chip can be used without operating system, but in order to realize the resource utilization of complex functions, improve the efficiency of hardware function utilization, simplify the development difficulty, and achieve real-time and multi-threaded work, it is necessary to use real-time embedded operating system, such as Linux, WinCE, VxWorks, UC/OS-II, QNX, TRON, etc. Linux and WinCE systems are suitable for multimedia, car navigation and entertainment systems; for VxWorks, UC/OS-II, QNX, TRON systems, based on fast startup and strong real-time performance, they are mostly used for automotive digital instrument display. I have successfully implanted UC/OS-II into MB86R01 and realized the multi-task real-time display of automotive digital instruments.

3 Conclusion

MB86R01 launched by Fujitsu is based on ARM9 chip, which is suitable for advanced navigation and video display in automotive applications. It can be made into digital virtual instrument display for automobiles to replace the mechanical instruments commonly used in automobiles. After the operating system is transplanted to ARM9, it is easy to realize multi-threaded and multi-task simultaneous display of instruments, such as playing audio and video at the same time when displaying information such as vehicle speed, rotation speed, water temperature, oil level, etc., and dual-screen display. The rapid development of embedded systems is bound to continuously promote the development of ARM technology. Based on the powerful ARM core of MB86R01, it has the advantages of small size, high performance, low power consumption, etc., and will definitely have broad development prospects.