In addition to usual program modeling of FPGA, the can use a method of direct debugging of real chains. Thanks to unlimited number of cycles of a of crystals of FPGA, operability of projects can be checked in real time instead of using a big of the test vectors necessary at program modeling.
Functional generators are realized in the form of 4-vkhodovy tables of transformation (Look-Up Table — LUT). Except use as functional generators, each LUT element can be also as the synchronous RAM dimension of 161 bits. Moreover, from two LUT elements within one section it is possible to realize the RAM dimension 162 bits either 321 bits, or the two-port RAM dimension of 161 bits.
The system of design of Virtex devices supports both program modeling and a method of debugging of directly hardware chains. For modeling performance the system takes the temporary information received after placement from a project database and enters it in the : list. The user can check also itself parts of the project, critical on time, using the static time TRACE analyzer.
The crystal of Virtex family contains two additional internal chains of scanning which can be involved by use in the project of the BSCAN macromodule. Conclusions of the SEL1 and SEL2 BSCAN macromodule are transferred to logical unit at the USER1 and USER2 teams, involving these chains. The limited liability partnerships given from an exit are read out by of the TDO1 or TDO2 BSCAN macromodule. The BSCAN macromodule also has separate clock entrances of DRCK1 and DRCK2 for each register PS, the general entrance of TDI and the general exits of RESET, SHIFT and UPDATE reflecting a condition of the controler of TAR port.
Algorithms of the PAR program support automatic the majority of projects. Nevertheless, in some appendices the if necessary can exercise control and control of process. A stage of input of the project the user can set the for splitting, placement and trace.
Some expanded properties of the software facilitate design of chips of Virtex. For example, circuit rather macroes (Relationally Placed Macros — RPMs) in which information on compulsory mutual orientation of components of elements of the project, give necessary information for their placement on a crystal. They help to provide optimum performance of standard logical functions.
Temporary requirements are introduced in the scheme in the form of direct restrictions, such as minimum admissible frequency of a, or the most admissible delay between two registers. At such approach the resulting speed of system taking into account the total extent of ways automatically is adjusted under the user's. Thus, the task of temporary restrictions for chains becomes not necessary.
Special routes of logic of the accelerated transfer can also for cascade turning on of functional generators at a of creation of functions with a large number of entrance variables.
Each KLB has four through lines — on one on each cell. These lines are used as additional entrances of data, or as additional route-making resources, not logical resources.
Created on the basis of the experience gained when developing the FPGA series, the Virtex family is the revolutionary step forward defining new standards in production of programmable logic. Combining a big variety of new system properties, hierarchy of and flexible route-making resources with the advanced silicon of production, the Virtex family gives to the developer opportunities of realization high-speed, a big logical of digital devices, at considerable decrease in time of development.
The environment of design supports input of hierarchical projects in which schemes of the top level contain the main functional while systems of the lower level define logical of these blocks. These elements of the hierarchical project of an unite by appropriate means at a placement stage in a crystal. At hierarchical realization various means of input of the project can unite, giving the chance each of parts to enter by the method suitable for it.
After food inclusion, the frequency of CCLK is equal 5 MHz. This frequency until loading of bits of ConfigRate then frequency on the new value determined by these bits. If in the project other frequency is not jammed, the frequency used by default is equal 4 MHz.