SoC digital display system design

This article takes the Virtex-II series Platform FPGA as an example to illustrate the flexibility, speed and low cost of using FPGA solutions for digital display system design.

System-on-Chip (SoC) solutions are hailed as one of the most important developments in the semiconductor industry. Currently, this device can be found in everything from consumer electronics such as digital mobile phones and digital TVs to high-end communication LAN/WAN equipment. In the past, to create such embedded systems, design engineers had to choose between three hardware components: processors, logic units, and memory. Now, these components have been merged into a single SoC solution.

Challenges facing SoC

Embedded system SoC can be realized by field programmable gate array (FPGA) or application specific integrated circuit (ASIC). Several key issues need to be solved in developing new SoC devices, including new design tools, advanced process technology and semiconductor IP. Although it is very advanced in technology, the ASIC-based SoC industry still faces challenges and may even find it difficult to fully realize its potential. The following are some of the problems and challenges it faces:

1. Increasing system complexity makes design errors and product delays more likely, while respins lead to higher costs.

2. Greater time-to-market pressure: There are many internal and external pressures to shorten time-to-market, because current design methods are still implemented according to traditional ASIC time schedules.

3. Product life cycles are shorter, and there is a stronger demand for design reuse of products with a life cycle of six months to one year.

4. Multiple industry standards coexist. Various new industry standards are constantly generated and updated, so it is difficult for products to keep pace with the changes in industry standards.

5. The design flexibility that can be used for different products is poor.

6. Lack of reconfiguration and field upgrade capabilities.

Now, SoCs based on FPGAs can solve tasks and challenges that SoCs based on ASICs could not accomplish before, such as field upgrades, reducing product time to market, and meeting emerging and updated standard requirements. SoC designs based on FPGAs can be used in a variety of situations, and the applications that benefit the most from the transition from ASICs to FPGAs include:

1. Communications and Networks: Networks and wireless infrastructure.

2. Data processing: servers and storage devices.

3. Consumer electronics: digital set-top boxes, digital televisions and personal video cameras.

ASICs have advantages in device cost, size and performance; while FPGAs have a slight advantage in time to market, modeling time and upgrade capabilities, which are the basic basis for weighing the trade-offs between FPGAs and ASICs in design. Compared with ASICs, the biggest difference between FPGAs and ASICs is that they use a large number of transistors and internal interconnects to achieve programming. Since ASICs use fewer transistors, the device cost of ASICs is usually lower than that of FPGAs in this respect. However, according to Moore's Law, the gap between FPGAs and ASICs in density, performance and device cost is gradually narrowing. As shown in Figure 1, chip interconnect technology, such as the use of more metal layers and copper wiring, helps to narrow the cost, density and performance gap between FPGAs and ASICs. In addition, when calculating the cost of a SoC based on ASICs or FPGAs, in addition to production costs, the time and money required for design and development are also important considerations.

The development process of Xilinx's programmable logic devices. FPGAs initially provided only a simple combination of logic solutions, and then developed into Platforms FPGAs, which provided great value to system architecture design engineers in terms of both functionality and total cost. Now, FPGAs have begun mass production from network equipment to high-end consumer devices. The following uses the Platform FPGA solution as an example to illustrate the characteristics of the SoC solution based on FPGAs.

Platform FPGA Solutions

Platform FPGA is a high-performance SoC solution. The following is a brief introduction to its features.

A. Platform FPGA model

The information age represented by the Internet, wireless, globalization and personal communications requires equipment manufacturers to increase data rates and channels in standard communication systems to support video, audio and data streams. Platform FPGAs provide manufacturers with the required system flexibility, time to market and support for high bandwidth requirements. In addition, Platform FPGAs provide system control for embedded processors, DSP cores for customer-customized data filtering and parallel processing, and gigabit serial and source synchronous I/O ports for system high-speed data communications.

Virtex-II system gate densities range from 40,000 to 8 million, providing embedded system memory. This high-density on-chip memory provides fast and efficient FIFO buffers, shift registers and CAMs, thereby increasing overall system bandwidth. Embedded RAM modules and high-speed memory interfaces provide a powerful, memory-based data path for systems with high bandwidth requirements.

The Platform FPGA functions provided by Virtex-II devices and their expansion devices can solve the problems of signal integrity, complex system clock management and on-board EMI management faced in system-level design.

B. Platform FPGA's soft and hard core

Platform FPGA is a flexible solution that integrates a series of soft and hard IP cores on a single chip, and the hardware and firmware can be upgraded at any time. The programmability of the FPGA architecture shortens the system development time, and a single Platform FPGA can meet the needs of multiple applications. In addition, it also provides the flexibility of hardware and software co-design, allowing design engineers to optimize the system during the development cycle.

Platform FPGAs use IP insertion and active interconnect technology. IP insertion technology allows soft and hard IP cores of any size or shape to be seamlessly inserted into any part of the FPGA architecture and maintain excellent connectivity with the surrounding array. Active interconnect technology provides active routing channels, allowing soft and hard IP cores to maintain stable and efficient performance no matter where they are located in the array.

Processor performance

EmPower! solutions for Platform FPGAs offer the highest performance programmable systems for embedded processors, while also offering the freedom to choose custom solutions. The embedded PowerPC405 microprocessor core it uses operates at 300MHz and offers over 420MIPs of performance. In addition, the MicroBlaze soft processor core on Virtex-II devices is a 32-bit RISC processor that operates at 125MHz and offers 82MIPs of performance.

The Virtex-II solution combines embedded multipliers and enhanced arithmetic functions, with Xtreme DSP functions exceeding 0.5T-MAC/s, which is more than 100 times faster than the industry's most advanced embedded DSP processor core. Combining Xilinx's system generator with MathWork's MATLAB and Simulink provides system and DSP design engineers with a complete set of familiar design tools.

In addition, SystemIO fully solves various system interconnection problems in high-performance design, including physical interfaces and protocols, to provide higher bandwidth. In order to enable Platform FPGA to support the fastest communication standards, such as 10G Ethernet, OC-192, Infiniband and XAUI interface standards, serial transceivers with speeds up to gigabits are integrated in the Virtex-II series FPGA. The SystemIO interface provides the most flexible solution to be compatible with some emerging interface standards, including RapidIO, LDT, SPI4, PCI66, PCI, FlexBus4 and POS-PHY4 parallel bus.

Platform FPGA SoC Application Examples

An example of a SoC digital display application based on Platform FPGA. A key problem that needs to be solved in digital video design is to realize the interface between different components and different products on the same circuit board. USB2.0, IEEE1394 and PCI can realize high-speed interface, while FPGA provides an ideal platform to provide interface and protocol conversion for different technologies.

Generally speaking, the foundation of digital video technology lies in digital image processing. In this solution, FPGA can provide excellent DSP processing capabilities, so digital image processing can be realized through programmable logic. FPGA provides an effective solution for encoding and decoding of digital video streams and is widely used in modules such as color space conversion functions, MPEG blocks, conversion rate control, and Read-Solomon and Viterbi decoders.

Display driver circuits using FPGAs are easy to program and can be used to control the complex timing signals required for display. They can also flexibly implement multiple versions that support different display components.

summary

Today's FPGA is a fast and effective development platform that can speed up the development cycle because it has a flexible architecture, advanced processing technology, powerful software integration technology and rich IP library, which can provide the most complete system integration solution.