Altera Corporation

Kok Yoong Foo

Boon Jin Ang

Kar Keng Chua

Thow Pang Chong

Choong Kit Wong

Joo Ming Too

Geok Sun Chong

Tze Haw Liew

Yan Jiong Boo

Circuits for a multiplier with a built-in accumulator and a method of performing multiplication with accumulation are disclosed. An embodiment of the disclosed circuits includes a logic circuit coupled to receive two inputs. The logic circuit is capable of generating a plurality of value bits from the inputs received. In one embodiment, the logic circuit includes a Booth recoder circuit that generates a plurality of partial products. A block of adders is coupled to logic circuit to receive and sum up the value bits. An adder adds the summation result from the block of adders to a previous accumulated value to generate intermediate sum and carry values. An accumulator, coupled to the adder, receives and stores the intermediate values.

Multiplier with built-in accumulator

A method of designing at IC is described. In one embodiment, the method includes providing an option to select a mask layer set from a plurality of mask layer sets, the plurality of mask layer sets including a first mask layer set and a second mask layer set, where the second mask layer set is an alternative mask layer option to the first mask layer set. In one embodiment, the method further includes receiving a selection from a user choosing a mask layer set from the plurality of mask layer sets. In one embodiment, the receiving occurs after design of the IC and prior to fabrication of the IC. Also, in one embodiment, the plurality of mask layer sets are predetermined mask layer sets. In one embodiment, the first mask layer set is a standard threshold voltage (SVT) mask layer set and the second mask layer set is a high threshold voltage (HVT) mask layer set. In one embodiment, core devices of the SVT mask layer set are SVT devices and some periphery devices of the SVT mask layer set are HVT devices. In one embodiment, hybrid cell (H-cell) devices of the HVT mask layer set are HVT devices and some periphery devices of the HVT mask layer set are HVT devices.

Method of designing integrated circuits including providing an option to select a mask layer set

Circuits, methods, and apparatus that provide the improvement or recovery of a duty cycle of a clock signal. One embodiment of the present invention receives a clock signal that may have a degraded duty cycle. The frequency of the clock signal is divided by two. The frequency-divided signal is delayed in order to generate two signals that are phase shifted from one another by 90 degrees. These signals are then exclusive-ORed together to generate a recovered clock. A control loop is provided to adjust the phase shift between the signals to be approximately 90 degrees.

Clock duty cycle recovery circuit

Growing community of inventors

Simpang Ampat, Malaysia

Kok Yoong Foo