The bit-wise operators operate on each bit from the same bit position of the operands and return a 1 bit value. If the sizes of the operands are not the same, the higher order bits of the smaller size operands are filled with 0's before an operation.

Following are the bit wise operators supported in VERA.

• ~ : Inversion Operation
• | : OR Operation
• & : AND Operation
• ^ : XOR Operation

• Computations include unknown bits, in the following way:
• ~x = x
• 0&x = 0
• 1&x = x&x = x
• 1|x = 1
• 0|x = x|x = x
• 0^x = 1^x = x^x = x
• 0^~x = 1^~x = x^~x = x
• When operands are of unequal bit length, the shorter operand is zero-filled in the most significant bit positions.

Following are the result of bitwise operation on various values.

Inversion

AND

OR

XOR

  1 program bitwise {
  2   bit [7:0] data = 8'hA0;
  3   bit [7:0] addr = 8'hA5;
  4   bit [15:0] mem_addr = 16'h1234;
  5   integer i = 32'hDEAD_BEEF;
  6   bit [7:0] result = 0;
  7   // Bitwise inversion
  8   printf("Inversion of %b               is %b\n",data, ~data);
  9   // Bitwise AND
 10   printf("AND       of %b with %b is %b\n",data, addr,data & addr);
 11   // Bitwise OR 
 12   printf("OR        of %b with %b is %b\n",data, addr,data | addr);
 13   // Bitwise XOR 
 14   printf("XOR       of %b with %b is %b\n",data, addr,data ^ addr);
 15   // Bitwise operation on integer and bit
 16   result = i | data;
 17   printf("OR        of %b with %b is %b\n",data, i,result);
 18   // Bitwise operation on different width operands
 19   mem_addr = data ^ i;
 20   printf("XOR       of %b with %b is %b\n",data, i,mem_addr);
 21 }

 Inversion of 10100000               is 01011111
 AND       of 10100000 with 10100101 is 10100000
 OR        of 10100000 with 10100101 is 10100101
 XOR       of 10100000 with 10100101 is 00000101
 OR        of 10100000 with 11011110101011011011111011101111 is 11101111
 XOR       of 10100000 with 11011110101011011011111011101111 is 1011111001001111

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