2 Replies Latest reply on Jul 23, 2012 5:22 AM by user_14586677

    multiplication ***int32

    gopalakrishnan.varadappan.2

      hai,

         

      i couldn't acquire a uint32 multiplication with the following code  (psoc creator),  it calculates wrongly some value. whats my mistake.

         

       

         

      #include

         

       

          <device.h>   

      uint32

       

          ball;   

      void

      main()

      {

       

      ball=4*24*3600;

       

      }

        • 1. Re: multiplication ***int32
          kenny.millar

            The compiler by deafault will treat the constants as 'int' and then do a basic 'integer' multiplication, storing the result into the uint32.

             

          You need to tell the compiler how to treat the constants, something like using an integer suffix like this:

             

           

             

          ball = 4ul x 24ul x 3200ul;

          • 2. Re: multiplication ***int32
            user_14586677

            I learned something from this post, reference material -

               

             

               

            Integer constants

               
                  
            • Integer constants can be one of the different bases:     
                      
              • a number starting with a digit from 1 to 9 followed only by digits from 0 to 9 is a decimal (base 10) constant, like 1 or 54321
              •       
              • if a number begins with '0x' or '0X' and is followed by digits from 0 to 9 and letters from a to f or from A to F, it is interpreted as a hexadecimal (base 16) constant, like 0xbeef or 0XDEAD
              •       
              • if a number begins with 0 and is followed by digits from 0 to 7, it is interpreted as an octal (base 8) constant, like 07 (which is the same as 7) or 0111 (which is NOT the same as 111)
              •      
            •     
            • integer constants in any of the three bases may be followed by an 'l' or 'L' to indicate a long constant, like 17l or 0xFfL
            •     
            • in ANSI C, an integer constant may be followed by:     
                      
              • a 'u' or 'U' to indicate an unsigned constant, like 33u
              •       
              • a 'ul' or 'UL' to indicate an unsigned long constant, like 32767ul
              •      
            •     
            • an integer constant takes on the minimum type necessary to be accurately represented, (possibly) starting as int and increasing from long to unsigned long     
                      
              • octal and hexadecimal constants, and (in ANSI C) constants ending with a 'u' or 'U' may also be unsigned (which can hold larger values than int but may have fewer bytes than long)
              •      
            •     
            • in ANSI C, 0 is always unsigned (perhaps to reduce ambiguity on machines with one's complement arithmetic)
            •     
            • as an example, if an int is 16 bits wide and a long is 32 bits wide, the following ranges would apply:
              Range   Decimal  Octal/Hexadecimal 0   unsigned unsigned 1-32767   int  int 32768-65535  long  unsigned 65536-2147483647 long  long 2147483648-429497295 unsigned long unsigned long 429497296-?  ???  ???
            •    
               

            Regards, Dana.