Abstract: The OSBS Subtractor Accelerator will enable the subtraction operation to simultaneously subtract all Bits of a data set, where: no ripple affect, no complement operations; therefore no multiple additions, no multiple moves, no temporary storage and no multiple instruction steps are required. In stand alone (pure) format the required time is six propagation delays to perform a subtraction operation. Beside the pure format a distributed or grouped format is available; which is dividing both input operands into groups. This grouped configuration also performs a parallel operation on the bits and on the groups in the same time. However, it needs nine propagation delays to execute a subtraction operation (including the first and second XOR gates); regardless it is a 16, 32 or 64 bit subtractor. It uses considerably less number of components than the pure configuration, and none of the integrated circuits have more than 5 input pins.

Abstract: The ONE STEP BINARY SUMMARIZER is a digital logic circuit. It is used for summarizing two binary numbers. It contains one Function Generator Module and one or more SUMMARIZER Units. For subtraction it is subtracting Register “A” from Register “B” and Register “B” from Register “A”. The two subtraction and one addition operations are executed simultaneously. The Function Generator Module determines the actual correct operation, (addition or subtraction) and selects the correct results for the resultant operand. The circuit utilizes the subtraction-by-carry method; therefore the subtraction operation does not require any presorting, complementary operations, iterative additions, temporary storage, and multiple instruction sets, etc. The logic-flow is similar, the operational speed is identical for the addition and subtraction operations; and therefore, it is a true Time Symmetrical circuit. It is independent from the initial operation selection, the signs and magnitudes of the input operands.