Search results
Results from the WOW.Com Content Network
Originally, Verilog was only intended to describe and allow simulation; the automated synthesis of subsets of the language to physically realizable structures (gates etc.) was developed after the language had achieved widespread usage. Verilog is a portmanteau of the words "verification" and "logic". [5]
% a simple AHDL up counter, released to public domain 13 November 2006 % % [block quotations achieved with percent sign] % % like c, ahdl functions must be prototyped % % PROTOTYPE: FUNCTION COUNTER (CLK) RETURNS (CNTOUT[7..0]); % % function declaration, where inputs, outputs, and bidirectional pins are declared % % also like c, square brackets indicate an array % SUBDESIGN COUNTER ( CLK ...
The counter itself must count in Gray code, or if the counter runs in binary then the output value from the counter must be reclocked after it has been converted to Gray code, because when a value is converted from binary to Gray code, [nb 1] it is possible that differences in the arrival times of the binary data bits into the binary-to-Gray ...
In the above example, IIf is a ternary function, but not a ternary operator. As a function, the values of all three portions are evaluated before the function call occurs. This imposed limitations, and in Visual Basic .Net 9.0, released with Visual Studio 2008, an actual conditional operator was introduced, using the If keyword instead of IIf ...
The built-in function name() returns an ASCII string for the current enumerated value, which is useful in validation and testing. New integer types : SystemVerilog defines byte , shortint , int and longint as two-state signed integral types having 8, 16, 32, and 64 bits respectively.
The advantage of choosing a primitive polynomial as the generator for a CRC code is that the resulting code has maximal total block length in the sense that all 1-bit errors within that block length have different remainders (also called syndromes) and therefore, since the remainder is a linear function of the block, the code can detect all 2 ...
A binary counter can represent 2 N states, where N is the number of bits in the code, whereas a straight ring counter can represent only N states and a Johnson counter can represent only 2N states. This may be an important consideration in hardware implementations where registers are more expensive than combinational logic.
Decade counter – modulus ten counter (counts through ten states). Up/down counter – counts up and down, as directed by a control input, or by the use of separate "up" and "down" clocks. Ring counter – formed by a "circular" shift register. Johnson counter – a twisted ring counter. Gray-code counter – outputs a sequence of Gray codes.