Embedded digital photo frame based on Blackfin processor

Today's embedded applications are everywhere, whether it is consumer electronics, communication terminals, or system equipment, industrial control, automotive electronic systems or aerospace, embedded applications are everywhere. Embedded has entered our life, in other words, our life will be inseparable from embedded in the future, the future development prospects are very impressive. Today, billions of microprocessors are produced every year around the world, most of which are widely used in various embedded systems.
At present, in terms of embedded system hardware platform, various microcontrollers and digital signal processor (DSP) products, whether in terms of brand, functional characteristics, or cost, processing power, power consumption requirements, integration, Depending on the specific requirements such as development cycle and technical difficulty, the hardware core platform with the most comprehensive advantages can be carefully selected. In terms of embedded operating systems, whether it is various commercial versions or free versions of the open source Linux camp, or "heavyweight" platforms such as WinCE and vxWorks, or Windows Mobile, Symbian, Android, etc. optimized for specific applications, It is also easy to choose an optimal operating system software platform.
The design process of embedded system is actually a process of joint development of software and hardware. When evaluating software and hardware platform selection, simply leaving the hardware to evaluate the operating system or leaving the operating system to evaluate the hardware platform is biased, especially for many non-general purpose processors. At present, many embedded hardware platforms provide operating systems and software module resources optimized for target applications. Some commercial operating systems are also optimized for mainstream hardware platforms, and many third-party optimized operating system versions are provided. These resources are of great significance for embedded system design. To this end, this paper introduces a unique embedded platform core processor, namely the converged processor Blackfin and its mainstream supporting operating system and related resources. Application and design method, if you have problems or dry goods here, you can privately, these I have also saved a lot of dry goods in the past year. First, I will briefly introduce the centralized design scheme of the embedded digital photo frame:
1. The choice of the hardware processor Blackfin
This design selects the converged processor Blackfin to construct a unique embedded hardware platform. The converged processor Blackfin is a micro-signal architecture (MSA) jointly developed by ADI and Intel. It integrates a 32-bit RISC-type instruction set, dual 16-bit multiply-accumulate (MAC) signal processing functions and general-purpose microcontrollers. Ease of use in one, this combination of converged processing power allows Blackfin processors to perform well in both semaphore and control applications, and eliminates the need for separate heterogeneous processors in many applications, This greatly simplifies hardware and software design. Blackfin processors are ideal for embedded audio, video, and communications applications where convergence is a key technology, including multi-format audio, video, language and image processing, multi-mode baseband and packet processing, control processing and real-time security processing. It is the design flexibility and scalability of this unique system architecture that has earned the Blackfin processor a wide range of adaptability for a wide range of applications in digital home entertainment, networking and streaming, automotive telematics and information Entertainment, digital radio, and mobile TV terminals.
Blackfin processors offer up to 756MHz performance in a single-core product with low power consumption as low as 0.8V. All Blackfin processors feature multiple independent DMA controllers that support automatic data transfers with minimal processor core overhead. In addition, the Blackfin processor also has a rich memory configuration, which can greatly facilitate the application development of embedded systems. Among them, ADSP-BF51x series processors have NOR flash memory, NAND flash memory, ferroelectric storage (FRAM), SDRAM, and also provide one-time programmable memory that supports Lockbox security technology.
The Blackfin processor architecture is fully SIMD compliant with instructions for accelerated video and image processing. This architecture is well suited for full signal processing/analysis applications. Because the Blackfin processor has the best code density and requires little (or no) code optimization, it does not encounter the performance headroom barriers common to other traditional processors.


2 The choice of uCLinux operating system
The choice of embedded operating system is just as important as the choice of embedded hardware microprocessor for a new embedded development project. For the Blackfin processor, in addition to the unique performance characteristics of the processor itself, powerful embedded operating system resources are also a key factor in the design of embedded systems. Blackfin processors support operating systems including VisualDSP's own operating system kernel (VDK), ThreadX, uCLinux, and Nucleas. This feature avoids the extended operating system change when porting the operating system from other processor platforms to the Blackfin platform. end product development cycle. Each operating system has different features and functions, as well as different terms such as prices and copyright fees. In terms of characteristics, embedded operating systems include VDK, an operating system with compact code and low complexity, and uClinux, an operating system with complex and rich features, INTEGRI TY, which is highly reliable, and RTA, which focuses on the needs of the automotive market. -OSEK et al. By analyzing the functions of various operating systems, the design finally chooses the uCLinux operating system to design the digital photo frame. Figure 1 shows the organization of its operating system on Blackfin.
    
Linux is a widely used embedded operating system. Among all mainstream embedded systems, the Linux operating system is characterized by its super network functions, arbitrary tailoring, completely free and universal Linux API features, and a wide range of Open resources make it an important force in embedded applications. uClinux is a Linux system for microprocessor applications. The source code is completely open. At the same time, according to the characteristics of embedded applications, uClinux has modified and recompiled the Linux kernel, so the kernel is smaller. uClinux also contains APIs commonly used by Linux, and retains the high stability, powerful network functions and excellent file system support functions of the original Linux operating system.
The uClinux operating system can run directly on the Blackfin processor. For many embedded applications, there are few solutions at the same price as Blackfin processors that can support Linux. In fact, Linux still presents many challenges when targeting specific embedded applications such as limited memory space or high security applications requiring real-time determinism. One of the main features of this design is that the Blackfin processor of ADI Company selected has integrated a large number of hardware drivers and application routines in uClinux, including wireless LAN drivers, audio/video codec drivers, etc. These drivers can help customers to easily port applications from the original system to the Blackfin platform. In addition, ADI and Arcturus Networks have jointly launched the new uCBF54x start-up development kit and system module. The software provided by the development kit includes the open source uCliunx BSP (Board Support Package) and Arcturus voice and management middleware, as well as a complete SIP and RTP stack. Therefore, it can be said that Blackfin Linux has become one of the most stable embedded Linux distribution packages in the field of embedded systems.


3 Software development tool environment
As the application of embedded system products becomes more and more complicated and the time for putting the products on the market becomes more and more urgent, a perfect development environment becomes more and more important. In addition to a full range of optimized embedded operating systems, having a complete development environment is also one of the important factors for its embedded system development. To this end, ADI also provides ADI CROSSCO RE software and hardware tools that support other Blackfin processors, including the VisualDSP++ integrated development and debugging environment, emulators, and EZ-KIT Lite evaluation hardware.
In addition, ADI also provides a large number of system service programs for embedded system development, such as software libraries that provide various common functions for embedded systems. These service programs are actually utility programs that can be used in any system. It runs in a stand-alone environment without RTOS installed, and can also be used in a VDK environment. These system service routines can easily and efficiently access the hardware subsystems of the Blackfin processor, including phase-locked loops, direct memory access, interrupt controllers, flag controllers and timers. A common set of AMs is available on all Blackfin processors, and a variety of applications and device drivers can also use these system service orderings. The software included in these system service programs has been repeatedly tested, and the performance is stable and reliable, and these programs can be used directly in the design. In addition, these modular software can also be easily integrated using these service programs, which, in fact, are provided with the VisualDSP++ integrated development environment.