Binary adder and multiplier circuit
View Patent ↗An adder circuit includes first through fourth two-bit adder modules, and first through third result mux blocks for receiving and adding first and second binary values to generate a final sum. A multiplier circuit that multiplies a multiplier and a multiplicand includes a multiplexer, an encoder connected to the multiplexer, a shifter connected to the encoder, and an accumulator connected to the encoder for receiving the multiplier and multiplicand and generating a multiplication product.
1. A multiplier circuit for multiplying a multiplier and a multiplicand, comprising:
a multiplexer having an input terminal for receiving the multiplier, wherein the multiplier includes first and second partial multipliers, a select input terminal for receiving a select signal, and an output terminal for providing at least one of the first and second partial multipliers based on the select signal;
an encoder connected to the output terminal of the multiplexer for receiving the at least one of the first and second partial multipliers, setting a most significant bit (MSB) of the at least one of the first and second partial multipliers to binary one, detecting a least significant set bit (LSB) in the at least one of the first and second partial multipliers, generating a position difference value that includes a difference between positions of first and second LSBs detected in current and previous multiplication cycles, respectively, and generating a result acknowledgement signal when the multiplication of the multiplier and the multiplicand is finished;
a shifter circuit connected to the encoder for receiving the position difference value and a first intermediate product, and generating a second intermediate product by right-shifting the first intermediate product by a count equal to the position difference value, wherein the second intermediate product includes a second MSB intermediate product and a second LSB intermediate product; and
an accumulator connected to the shifter circuit for receiving the second MSB intermediate product and the multiplicand, adding the multiplicand to the second MSB intermediate product to generate a first MSB intermediate product, appending the first MSB intermediate product to the second LSB intermediate product to generate a third intermediate product, and transmitting the third intermediate product to the shifter circuit,
wherein the accumulator generates the first intermediate product in the previous multiplication cycle, wherein a final product of the multiplier and the multiplicand is generated subsequent to the encoder detecting each set bit in the at least one of the first and second partial multipliers.
2. The multiplier circuit of claim 1 , further comprising a control logic circuit for generating the select signal based on a detection of one or more set bits in the at least one of the first and second partial multipliers.
3. The multiplier circuit of claim 1 , wherein the first partial multiplier includes an MSB half of the multiplier.
4. The multiplier circuit of claim 1 , wherein the second partial multiplier includes a LSB half of the multiplier.
5. A method for multiplying a multiplier and a multiplicand, the method comprising:
receiving the multiplier including first and second partial multipliers;
selecting at least one of the first and second partial multipliers;
setting a most significant bit (MSB) of the at least one of the first and second partial multipliers to binary one;
detecting a least significant set bit (LSB) of the at least one of the first and second partial multipliers;
generating a position difference value that includes a difference between positions of first and second LSBs detected in current and previous multiplication cycles, respectively;
generating a second intermediate product by right-shifting a first intermediate product by a count equal to the position difference value, wherein the second intermediate product includes a second MSB intermediate product and a second LSB intermediate product;
adding the multiplicand to the second MSB intermediate product to generate a first MSB intermediate product;
appending the first MSB intermediate product to the second LSB intermediate product to generate a third intermediate product; and
generating a result acknowledgement signal when the multiplication of the multiplier and the multiplicand is finished and a final product is generated, wherein the final product of the multiplier and the multiplicand is generated subsequent to detecting each set bit in the at least one of the first and second partial multipliers.
6. The method of claim 5 , wherein the first partial multiplier includes an MSB half of the multiplier.
7. The method of claim 5 , wherein the second partial multiplier includes a LSB half of the multiplier.