An arithmetic logic unit is disclosed that includes a first logical circuit that generates a first partial sum result from three operands in a first stage of a single clock cycle of a processor; a second circuit that generates a second partial result in the same first stage of the clock cycle of the processor; and an adder that receives the first partial result from the first logical circuit and the second partial result from the second circuit and generates a secondary result during a second stage of the single clock cycle of the processor. The arithmetic logic unit may optionally further include a backend circuit that performs additional arithmetic and logic functions in the same single clock cycle of the processor.

A line driver circuit is configured to provide a high spurious free dynamic range output and includes first and second output transistors and a control circuit. The first output transistor is controllable to pull an output node to a logic high state, and the second output transistor is controllable to pull the output node to a logic low state. The first control circuit is connected to a control input of the first output transistor and configured to establish a control signal at the control input of the first output transistor while the second output transistor is in a low impedance operating state to reduce an imbalance in turn-on delay between the first output transistor and the second output transistor.

A line driver circuit is configured to provide a high spurious free dynamic range output and includes first and second output transistors and a control circuit. The first output transistor is controllable to pull an output node to a logic high state, and the second output transistor is controllable to pull the output node to a logic low state. The first control circuit is connected to a control input of the first output transistor and configured to establish a control signal at the control input of the first output transistor while the second output transistor is in a low impedance operating state to reduce an imbalance in turn-on delay between the first output transistor and the second output transistor.

Disclosed is a parallel prefix adder structure with a carry bit generation circuit that generates primary carry bits for only some bit pairs and a sum circuit with ripple carry adders that use these primary carry bits to generate secondary carry bits and sum bits for a final sum. The carry bit generation circuit has different sections, which process different sequential sets of bit pairs and which have different sparsity configurations. As a result, generation of the primary carry bits is non-uniform. That is, in the different sections the primary carry bits are generated at different carry bit-to-bit pair ratios (e.g., the carry bit-to-bit pair ratios for the different sections can be 1:2, 1:4, and 1:2, respectively). For optimal performance, the specific bit pairs for which these primary carry bits are generated varies depending upon whether the maximum operand size is an odd number of bits or an even number.

Disclosed is a parallel prefix adder structure with a carry bit generation circuit that generates primary carry bits for only some bit pairs and a sum circuit with ripple carry adders that use these primary carry bits to generate secondary carry bits and sum bits for a final sum. The carry bit generation circuit has different sections, which process different sequential sets of bit pairs and which have different sparsity configurations. As a result, generation of the primary carry bits is non-uniform. That is, in the different sections the primary carry bits are generated at different carry bit-to-bit pair ratios (e.g., the carry bit-to-bit pair ratios for the different sections can be 1:2, 1:4, and 1:2, respectively). For optimal performance, the specific bit pairs for which these primary carry bits are generated varies depending upon whether the maximum operand size is an odd number of bits or an even number.

Disclosed is a parallel prefix adder structure with a carry bit generation circuit that generates primary carry bits for only some bit pairs and a sum circuit with ripple carry adders that use these primary carry bits to generate secondary carry bits and sum bits for a final sum. The carry bit generation circuit has different sections, which process different sequential sets of bit pairs and which have different sparsity configurations. As a result, generation of the primary carry bits is non-uniform. That is, in the different sections the primary carry bits are generated at different carry bit-to-bit pair ratios (e.g., the carry bit-to-bit pair ratios for the different sections can be 1:2, 1:4, and 1:2, respectively). For optimal performance, the specific bit pairs for which these primary carry bits are generated varies depending upon whether the maximum operand size is an odd number of bits or an even number.

Disclosed is a parallel prefix adder structure with a carry bit generation circuit that generates primary carry bits for only some bit pairs and a sum circuit with ripple carry adders that use these primary carry bits to generate secondary carry bits and sum bits for a final sum. The carry bit generation circuit has different sections, which process different sequential sets of bit pairs and which have different sparsity configurations. As a result, generation of the primary carry bits is non-uniform. That is, in the different sections the primary carry bits are generated at different carry bit-to-bit pair ratios (e.g., the carry bit-to-bit pair ratios for the different sections can be 1:2, 1:4, and 1:2, respectively). For optimal performance, the specific bit pairs for which these primary carry bits are generated varies depending upon whether the maximum operand size is an odd number of bits or an even number.

A non-destructive memory array implements a full adder. The array includes a column connected by a bit line and a full adder unit. The column stores a first bit in a first row of the bit line, a second bit in a second row of the bit line, and an inverse of a carry-in bit in a third row of the bit line. The full adder unit stores, in the second and third rows of the bit line, a sum bit and a carry out bit output, respectively, of adding the first bit, the second bit and the carry-in bit. The full adder unit does not overwrite any of the bits when a full adder table indicates that the sum bit and the carry out bit are equivalent to the second bit and the carry-in bit.

A non-destructive memory array implements a full adder. The array includes a column connected by a bit line and a full adder unit. The column stores a first bit in a first row of the bit line, a second bit in a second row of the bit line, and an inverse of a carry-in bit in a third row of the bit line. The full adder unit stores, in the second and third rows of the bit line, a sum bit and a carry out bit output, respectively, of adding the first bit, the second bit and the carry-in bit. The full adder unit does not overwrite any of the bits when a full adder table indicates that the sum bit and the carry out bit are equivalent to the second bit and the carry-in bit.

A logic cell for a programmable logic integrated circuit having K function inputs, where K is the largest number such that the logic cell can compute any function of K inputs, and where the logic cell is configurable to implement one bit of a counter in parallel with any independent function of K-1 of the K inputs.