Detailed Description

The ROLOperator rotates bits in a value to the left by Amount.

The bits rotated out to the left, are rotated back in from the right. In other words, when rotating 1 bit left, the most significant bit becomes the least significant bit, and all the other bits move one bit to the left.

Arguments

When operator is used inside a signal its default input is automatically tied to signal's InternalValue or previous operator's output. Its default output is automatically tied to next operator's input or to signal's Value. See also CDP Operator Usage In CDP Signals.

Example

To rotate a signal value 3 bits to the left, add a ROLOperator<unsigned short> into a Signal<unsigned short> in Configure mode. Then go into the ROLOperator that was added, and set Amount to 3.

How to Run the Example

To run the example from CDP Studio, open Welcome mode and find it under Examples. Next, in Configure mode right-click on the system project and select Run & Connect. See the Running the Example Project tutorial for more information.

Set the signal Value containing the ROL operator to 0xff00 (65280), and verify that the value after the operator has been applied becomes 0xf807 (63495)

Actual Processing Code of the ROLOperator

unsigned int ROLOperator<T>::Process()
{
  if (!m_amountToRotate)
    return STATUS_ERROR;

  const T input = static_cast<T>(m_input);
  uint64_t shift_amount = static_cast<T>(*m_amountToRotate);
  uint64_t rightshift_val = (m_bitSize-shift_amount) % m_bitSize;

  uint64_t lower = input >> rightshift_val;
  uint64_t upper = input << shift_amount;
  m_output = static_cast<T>(upper | lower);
  return STATUS_OK;
}