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7.5.4 ROL

Function​

Loop left shift, move the operand input in IN to the left by N bits in binary bits, and add the overflow bits on the left to the right. Finally, the result is output in OUT

LD graphics​

Alt text

  • The following figure illustrates how to rotate the integer data type operand to the left by 5 bits:

alt text

Parameter description​

Interface variableDeclarationData typeDescription
INVar_InputANY_BITThe operand to be rotated left
NVar_InputANY_INTNumber of digits to rotate left
Function nameReturn valueANY_BITValue after circular left shift
warning
  • Here ANY_BIT data type is BYTE, WORD, DWORD, LWORD;
  • BOOL has no meaning, the return value type is the same as IN type

Example​

  • LD example is shown below:

alt text

  • ST example is shown in the following code:
wVar:=ROL(IN:=wVar,N:=nVar);