logic

问题 Say I need a signal to represent numbers from 0 to 5; obviously this needs 3 bits of std_logic to be represented ( i.e if MAXVAL=5, then bitwidth= { wcalc "floor(logtwo($MAXVAL))+1" } ). I'm aware I could do: SIGNAL myLogicVector : STD_LOGIC_VECTOR(2 downto 0) := 5; with which I'd explicitly specify an array of three std_logic 'bits', and set initial value; then I could use REPORT to print out the length (in this case, 3): report("Bit width of myLogicVector is "& integer'image(myLogicVector

问题 This question already has answers here : Logical operators in JavaScript — how do you use them? (2 answers) Closed 4 years ago . When I type in browser's console: console.log(2 && 3) it results always with second number (in this case 3): 3 Can someone explain me why? 回答1: If the left hand side of && evaluates as a false value, the whole expression evaluates as the left hand side. Otherwise it evaluates as the right hand side. 2 is a true value, so 2 && 3 is 3 . For comparison, try console.log

问题 I posted an answer to another stackoverflow question which requires some digital logic to be implemented in Verilog or VHDL so that it can be programmed into an FPGA. How would you implement the following logic diagram in Verilog, VHDL, or any other hardware description language? The numbered boxes represent bits in a field. Each field has K bits, and the bits for current and mask will be provided by a computer system (using a latched register or equivalent). The bits in next will be read

问题 I'm trying to convert a binary tree e.g. OR (Implementation of Operator - a specialisation of TreeNode... see below) |-A (Implementation of TreeNode... see below) |-OR |-B |-AND (Implementation of Operator - a specialisation of TreeNode... see below) |-C |-OR |-D |-E into it's equivalent Conjunctive Normal Form (CND) representation. I believe that because I'm only using the logical OR + AND operators that the only step I'd have to perform is the distribution of AND over OR. This would produce

问题 I've searched the web but I've found no solution to this problem. What is the logical priority for operators NAND , NOR and XNOR ? I mean, considering as example the expression A AND B NAND C which operator should be evaluated first? Obviously NAND can be translated as NOT-AND (as NOR is NOT-OR and XNOR is NOT-XOR ), but (A AND B) NAND C != A AND (B NAND C) = A AND NOT(B AND C) According to my researches there's no a defined priority for such an expression, so I think the simplest solution is

问题 I currently have the following code and the data is displayed fine. <logic:iterate name="myList" id="product" indexId="iteration" type="com.mycompany.MyBean"> <tr> <td> <bean:write name="product" property="weight"/> </td> <td> <bean:write name="product" property="sku"/> </td> <td> <bean:write name="product" property="quantity"/> </td> </tr> </logic:iterate> But now I need to make the "quantity" part modifiable. The user should be able to update that field, press submit and when its sent to

问题 NOTE: **Please read all other related questions :** Here is my first and second attempts at asking this question: Efficient way to determine the outcome of test matrix Would cartesian product be the best approach for this Here is the problem: I have several ( like 20 ) Boolean validations ( true / false ) All Boolean validations as a whole also have a validation Result I'm trying to find the best solution to test all the validations and also the validation result. I was looking into a Matrix

问题 Currently, I am learning some FPGA design techniques using VHDL, my problem is whether we can use := and <= interchangeably in VHDL or not, though I've seen the use of := in constants declarations and <= in assignments? Thanks in advance! 回答1: The rules are a little more complex than this, but basically: you use <= to do signal assignment, which takes effect on the next delta cycle. You use := to do variable assignment, which takes place immediately. So if you have a signal, you always use <=

问题 Is it possible to convert a string to an operator for use in a logical condition. For example if(x Convert.ToOperator(">") y) {} or if(x ">" as Operator y){} I appreciate that this might not be standard practice question, therefore I'm not interested in answers that ask me why the hell would want to do something like this. Thanks in advance EDIT: OK I agree, only fair to give some context. We have system built around reflection and XML. I would like to be able to say something like, for ease.

问题 I'm building a PHP class with a private member function that returns a string value such as: 'true && true || false' to a public member function. (This string is the result of some regex matching and property lookups.) What I'd like to do is have PHP parse the returned logic and have the aforementioned public function return whether the boolean result of the parsed logic is true or false. I tried eval(), but I get no output at all. I tried typecasting the boolean returns...but there's no way