摘要:
A circuit for latching inputs and enabling outputs on a bidirectional pin using a PLL lock detect circuit is disclosed. A PLL lock detect circuit generates an active lock control signal when an output reference signal is phase locked relative to an input reference signal applied to a phase locked loop (PLL) circuit. A latch and enable circuit is responsive to this lock control signal to latch the input signal (off of the pin), and, thereafter, enable output of an output signal onto the bidirectional pin. The latch and enable circuit includes a data latch to store the input signal when the lock control signal goes to an active state. The latch and enable circuit also includes a delay circuit to delay the lock control signal to produce a delayed lock control signal, and a tristateable output driver that is tristated when the delayed lock control signal is inactive, but, operates to pass (i.e., enable) the output signal to the bidirectional pin when the delayed lock control signal is active.
摘要:
An apparatus comprising a first circuit and a second circuit. The first circuit may be configured to generate an output signal that ramps between a first and second frequency in response to (i) a first control signal, (ii) a second control signal, and (iii) a first reference signal. The second circuit may be configured to generate the first and second control signals in response to a third control signal having a third frequency. The third frequency may reduce electromagnetic interference generated by the first circuit.
摘要:
An apparatus comprising a first circuit and a second circuit. The first circuit may be configured to generate an output signal that ramps between a first and second frequency in response to (i) a first control signal, (ii) a second control signal, and (iii) a first reference signal. The second circuit may be configured to generate the first and second control signals in response to a third control signal having a third frequency. The third frequency may reduce electromagnetic interference generated by the first circuit.
摘要:
An apparatus comprising a latch circuit, a non-volatile storage circuit, and a switching circuit. The latch circuit may be configured to be dynamically programmable. The non-volatile storage circuit may be configured to be re-programmable. The switching circuit may be configured to transfer data from (i) the non-volatile memory element into the latch circuit in response to a first control signal and (ii) the latch circuit into the non-volatile memory circuit in response to a second control signal.
摘要:
A register using a single pin to provide two or more control signals (e.g., clock and data signals). The present invention decodes a three state input waveform to generate a clock/write signal and uses a three state clock waveform to generate a clock/read data signal. The present invention generally comprises a three-level receiver, a latch and an output driver to form a one-pin bidirectional interface used with a shift register. To write, the interface converts a three-level input signal into separate clock and data signals which drive the shift register. To read, the interface converts a bi-level input signal into a three-level output signal representing the output of the shift register. As a result, the present invention allows the programming of a device such as an erasable programmable read only memory (EPROM) in a clock chip while utilizing the fewest number of pins.
摘要:
A register using a single pin to provide two or more control signals (e.g., clock and data signals). The present invention decodes a three state input waveform to generate a clock/write signal and uses a three state clock waveform to generate a clock/read data signal. The present invention generally comprises a three-level receiver, a latch and an output driver to form a one-pin bidirectional interface used with a shift register. To write, the interface converts a three-level input signal into separate clock and data signals which drive the shift register. To read, the interface converts a bi-level input signal into a three-level output signal representing the output of the shift register. As a result, the present invention allows the programming of a device such as an erasable programmable read only memory (EPROM) in a clock chip while utilizing the fewest number of pins.
摘要:
A programmable circuit for generating a clock signal is disclosed. The present invention provides a clock generator architecture that combines PLL-based clock generator circuitry with an on-chip EPROM in a monolithic clock generator chip. The clock generator allows for electrical configuration of various information including PLL parameters, input thresholds, output drive levels and output frequencies. The various parameters can be configured after the clock generator is fabricated. The parameters can be configured either during wafer sort or after packaging. The clock generator can be erased prior to packaging so programming can be verified.
摘要:
A multi-stage apparatus used as a voltage controlled oscillator. Each stage includes a first complementary differential current switch and a second complementary differential current switch with a second set of complementary differential current switches having a first complementary differential current switch and a second complementary differential current switch, the two sets of complementary differential current switches are connected in a push pull arrangement. In this arrangement, the outputs of the first complementary differential current switch of the first set of complementary differential current switches and the first complementary differential current switch of the second set of complementary differential current switches are connected with the input of the second complementary differential current switch of the first set of complementary differential current switches. The outputs of the second complementary differential current switch of the first set of complementary differential current switches and the second complementary differential current switch of the second set of complementary differential current switches are connected with the input of the first complementary differential current switch of the second set of complementary differential current switches. A controlled complementary voltage clamp is connected to the output nodes of the first set of complementary differential current switches and a controlled complementary voltage clamp is connected to the output nodes of the second set of complementary differential current switches.
摘要:
An apparatus comprising a latch circuit, a non-volatile storage circuit, and a switching circuit. The latch circuit may be configured to be dynamically programmable. The non-volatile storage circuit may be configured to be re-programmable. The switching circuit may be configured to transfer data from (i) the non-volatile memory element into the latch circuit in response to a first control signal and (ii) the latch circuit into the non-volatile memory circuit in response to a second control signal.
摘要:
An apparatus comprising a storage circuit, a load circuit and an oscillator circuit. The storage circuit may be configured to store a number of configuration bits configured to provide one or more control signals. The load circuit may be configured to provide a variable magnitude load in response to the one or more control signals. The oscillator circuit may be configured to provide an output signal, where the output signal has (i) a frequency determined in response to the magnitude of the load circuit and (ii) a magnitude generated in response to a current generated in response to an output of a clamp circuit.