Abstract: A high-speed, half rate phase detector provides an effective solution to the problem of XOR gate response to the minimum width signal precursors (Q1 and Q2) of a phase signal that indicates a phase difference between a data signal and a clock signal by combining the precursor signals in a multiplexer and combining the multiplexed signal with the data signal in an XOR gate. This affords the transition information in the transitions of the precursor signals, which is significant of phase difference, without requiring the XOR gate to respond to the minimum widths of those pulses.

Abstract: Circuitry for a phase locked loop (PLL) includes a reference signal input and a frequency doubler. The output of the frequency doubler is a second reference signal having a frequency that is approximately twice that of the initial reference signal, and which is fed into the PLL. The frequency doubler includes a first delay circuit having an input coupled to the input of the frequency doubler; and an XOR circuit having a first input coupled to an output of the delay circuit and a second input coupled to the input of the frequency doubler. The frequency doubler can include one or more additional delay circuits in series after the first delay circuit, the output of which is provided to a multiplexer. The multiplexer includes a selection signal input for selecting an output from at least one of the delay circuits to be provided to the XOR circuit. The frequency doubler allows the PLL to have a smaller feedback divider ratio and a higher loop gain for reducing jitter.

Abstract: A programmable phase locked-loop (PLL) active filter circuit is provided which includes networks of cooperating bandwidth tuning components to select bandwidth ranges. The values and arrangement of the network of selectable series input (R1) resistors are chosen to be useful in both low band and high band settings. Likewise, the opamp network of feedback resistors (R2) and capacitors (C1) values are chosen to be useful in both low band and high band applications, automatically pairing with the R1 selection in response to a bandwidth range selection. These tuning components, internal to an integrated circuit, can be used for a plurality of wideband loops. External components can be used to supplement the internal components for low and high bandwidth applications.

Abstract: A configurable PLL architecture having multiple detection elements. The configurable PLL circuit includes a first detector for providing a first differential signal, a second detector for providing a second differential signal, a third detector for providing a third differential signal, and a selection circuit for enabling at least one of the first, second and third detectors. The PLL circuit also includes a multiplexer for receiving at least one differential signal from a corresponding enabled detector, and for providing a multiplexed differential signal output. In operation, an operating mode is selected, and one or more detectors are enabled for operation with one or more input reference signals. The outputs of the enabled detectors is received by the multiplexer to complete the operation of the selected operating mode.

Abstract: A configurable multiplexing circuit and arrangement suited for phase locked loop applications. The multiplexing circuit includes an EX-OR element, a multiplexer element and a summer element. Each element is configured for receiving a particular type of detection signal output, as an input for one of multiple selectable multiplexing operations. The multiplexing circuit further includes a selection signal input, coupled to the EX-OR element, the multiplexer element and the summer element, for receiving a selection signal that enables one or more of the EX-OR element, the multiplexer element, and the summer element. Non-enabled elements are powered down to eliminate jitter and performance penalties.

Abstract: A circuit and method comprising a memory, a first latch, a second latch and a control circuit. The memory may be configured to write information in response to (i) an input data signal and (ii) an address signal. The first latch may be configured to hold the address in response to a control signal. The second latch may be configured to hold the data input signal in response to the control signal. The control circuit may be configured to present the control signal in response to (i) an enable signal and (ii) a detect signal.

Abstract: A memory array having a physical depth of 2N-bits (N being an integer) includes control and data bus logic configured to control read and/or write operation in the memory array and to select the depth of the memory array. The control logic may include upper and lower byte control circuitry and the depth of the array may be selected from a group consisting of xN-bits and 2xN-bits, x being an integer. The control and data bus logic may be implemented as metal options within the device to be selected during fabrication to achieve a desired array depth.

Abstract: A reference voltage generator may include an input for receiving a first voltage for input to a sense amp. The reference voltage generator may also include an output for outputting a second voltage for input to the sense amp. The second voltage is influenced by the first voltage. Alternatively, a reference voltage generator may include a first input for receiving a first voltage on a first bitline. The reference voltage generator may also include a first output for outputting a second voltage on a second bitline. The second voltage is influenced by the first voltage. Alternatively, a reference voltage generator may include a first input for receiving a first voltage on a first transmission busline. The voltage generator may also include a first output for outputting a second voltage on a second transmission busline. The second voltage is influenced by the first voltage.

Abstract: A circuit and method comprising a memory, a first latch, a second latch and a control circuit. The memory may be configured to write information in response to (i) an input data signal and (ii) an address signal. The first latch may be configured to hold the address in response to a control signal. The second latch may be configured to hold the data input signal in response to the control signal. The control circuit may be configured to present the control signal in response to (i) a detect signal and (ii) a transition of the address signal.

Abstract: A circuit comprising a sense amplifier, an evaluation circuit, a control circuit and a register circuit. The sense amplifier circuit may be configured to present a first output and a second output in response to (i) an input signal and (ii) an enable signal. The evaluation circuit may be configured to present an evaluation signal in response to the first and second outputs. The control circuit may be configured to present (i) a first clock signal, a second clock signal and an enable signal in response to (i) the evaluation signal and (ii) a wordline signal. The register circuit may be configured to hold either the first or second output in response to the first and second clock signals. The register circuit may be implemented as a master-slave register that may respond to the first and second clock signals.

Abstract: A memory device includes a random access memory (RAM) cell accessible through a RAM wordline and coupled between first and second bitlines; a read only memory (ROM) cell accessible through a ROM wordline and having an output coupled to the first bitline and an input configured to receive a first voltage signal; and a reference voltage generator having a first input coupled to the first bitline, a second input configured to receive the first voltage signal, and an output coupled to the second bitline. The memory device may further include a bitline load having an output coupled to the first bitline. A virtual ground driver configured to produce the first voltage signal may be coupled to the input of the read only memory cell. Further, column select pass gates configured to be under the control of a logic signal and having a first input coupled to the first bitline, a second input coupled to the second bitline, a first output and a second output may be provided.

Abstract: The present invention significantly lowers the continuous write cycle ICC, thus lowering the overall ICC specification, for multi-port (and single port) memory devices without significant changes in ICC.sub.WR and ICC.sub.RR currents. In one embodiment, a circuit for the generation of a Write Data select signal (i.e., TTL.sub.-- SEL) according to the present invention employs a unique "write power-down" delay (t.sub.WPD) which is a function of "CE+WE" (chip select and write enable) and incorporates the delay into the generation of the Write Data select signal, TTL.sub.-- SEL. The delay t.sub.WPD is provided by a delay device and is preferential. That is, a delay is provided when the internal write data select signal, i.e., TTL.sub.-- sel (which is a function of "CE+WE"), transitions from logic "1" to a logic "0", but no delay is produced when TTL.sub.-- sel transitions from a logic "0" to a logic "1".