Introduction

Generator then propagates signal types and precisions as appropriate. The automatically chosen type is the least expensive that preserves full precision. Translations from signed to unsigned and vice versa are automatic as well.

System Generator also allows designs to contain elements that cannot be realized in hardware, but assist development and debugging. Examples of such elements are signal sources, scopes, and machinery that tracks the divergence between fixed point and double precision calculations. System Generator automatically discards such elements when asked to translate to hardware.

Hardware Handshaking

In Simulink, time evolution is defined by sample rates for each block in the system. There are propagation rules along signals so that not every block need set an explicit sample period. This is extremely flexible, but has implications for modeling hardware. Sequential circuits are clocked, and a key aspect of designing, especially multirate systems, is the interplay between clock and clock enable signals. Although abstracted, a bit and cycle true simulation must have mechanisms for defining and controlling clocked behavior in the system model.

Every signal has a fixed point value as defined in the previous section. In addition, it carries an implicit boolean valid bit that can be used to achieve hardware handshakes between blocks. For example, upon startup, a pipeline may define its output invalid until it has flushed its pipe. By inspecting the valid bits of its inputs, a block can determine how to process its input data.

Multirate Systems

Multirate systems can be implemented in System Generator by using sample rate conversion blocks for up-sampling and down-sampling. The necessary control logic is automatically generated when the design is netlisted. Before netlisting, the sample rates in the system are normalized to integer values; in hardware, the system clock period corresponds to the GCD of the integer sample periods. Clock enables are used to activate the hardware blocks at the appropriate moment in time with respect to the system clock.

Consider for example, the multirate system model shown in the figure below, which consists of I/O registers, an up-sampler, an anti-aliasing filter, and a down-sampler. The input signal is up-sampled by a factor of two, and subsequently down-sampled by a factor of three, giving an overall sample rate conversion by a factor of 2/3. The ST blocks in the system model extract the sample period from a Simulink signal, which can then be displayed. In the example, the input sample period is one. In the generated hardware implementation shown below the system model, each element is driven by the system clock, with its respective clock enable driven according to its sample period in the original system model.

Figure 1-2: Example of a multirate system model

Hardware Handshaking

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Xilinx V2.1 manual Hardware Handshaking, Multirate Systems
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V2.1 specifications

Xilinx V2.1 is a notable iteration in the series of versatile and robust Field-Programmable Gate Arrays (FPGAs) developed to cater to a wide range of applications. Launched to provide enhancements in performance and flexibility, V2.1 embodies sophisticated technologies and features that stand out in the electronics industry.

One of the primary features of Xilinx V2.1 is its improved processing power. The architecture has been optimized to support higher clock speeds and increased logic density, allowing for more complex designs to be implemented effectively. This boost in performance is facilitated by utilizing advanced silicon technologies, which significantly reduce power consumption while maximizing efficiency.

Another significant characteristic of Xilinx V2.1 is its enhanced I/O (Input/Output) capabilities. The device supports a variety of industry-standard interfaces, which include PCI Express, SATA, and various serial communication protocols. Such adaptability ensures seamless integration into existing systems, providing engineers with the flexibility to adapt to various application requirements without the need for substantial redesign efforts.

Xilinx V2.1 also features improved scalability, making it a prime choice for applications that demand diverse performance levels. This device supports an array of configurations and can be used in small-scale projects as well as in larger, more demanding environments requiring extensive resources. This scalability is further aided by support for multiple development platforms, enabling rapid prototyping and simplifying the design process.

Security is increasingly becoming a priority in digital design, and Xilinx V2.1 addresses this concern via hardware security features. It includes enhanced encryption protocols and secure boot functionalities, which help protect intellectual property and sensitive data from unauthorized access.

Additionally, the integration of advanced DSP (Digital Signal Processing) blocks allows Xilinx V2.1 to efficiently handle data-intensive tasks such as video processing and real-time signal analysis. These capabilities make it suitable for applications in telecommunications, automotive systems, and industrial automation.

Xilinx V2.1 also benefits from a rich development environment, including robust software tools that facilitate design entry, simulation, and verification. The support for industry-standard programming languages like VHDL and Verilog simplifies the development process, enabling engineers to design complex systems more efficiently.

In summary, Xilinx V2.1 stands out due to its impressive combination of high performance, flexibility, scalability, security, and comprehensive development support. These features make it a valuable asset for engineers and developers looking to innovate across various sectors, from telecommunications and automotive to industrial applications.
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