Cypress Semiconductor Corporation

At&e Corporation

Seiko Epson Corporation

Seiko Corporation

Russell R Moen

Mark R Gehring

Richard R Suter

Nathan Y Moyal

Brent R Jensen

Lawrence Ragan

Eric P Mitchell

Joseph D Stenger

A method of communication between a first transceiver having a first local oscillator set at a first frequency and a second transceiver having a second local oscillator set at a second frequency disclosed. The method includes transmitting a first signal at a first frequency from the first transceiver to the second transceiver, transmitting a second signal at the second frequency from the second transceiver to the first transceiver, and receiving the second signal at the first transceiver. The method further includes maintaining the first local oscillator at the first frequency and the second local oscillator at the second frequency during the transmitting of the first signal, during the receiving of the first signal, during the transmitting of the second signal, and during the receiving of the second signal.

Circuit and method for selectable high/low side injection in an intermediate frequency transceiver

A transmitter digital signal processor (DSP) circuit has a transmit frequency represented by n-bit data output from a look up table (LUT). The n-bit data is outputted to an n-bit accumulator structured to overflow at a rate based on the output n-bit data to output a phase. The circuit further has device structured to add an n-bit signed constant to the accumulator to offset the frequency represented by the n-bit data output from the LUT. A transceiver on a semiconductor chip may include as part of a transmitter circuit, a transmit DSP circuit that has the LUT, accumulator and device providing an n-bit signed constant to the accumulator to offset a transmit frequency in order to allow a receiver circuit on the transceiver to communicate directly with the transmitter circuit, and thus allowing testing of the transceiver.

Frequency offset and method of offsetting

A crystal oscillator circuit which does not produce runt pulses when the oscillator is turned on or off. The circuit includes a crystal oscillator, an integrator which integrates the energy in a plurality of pulses, a threshold circuit which is active when the output of the integrator reaches a pre-specified threshold and gating circuits which gate the output of the crystal oscillator to the output terminal only when the threshold circuit has reached the specified threshold.

Circuit and method to eliminate startup and shutoff runt pulses from crystal oscillators

An apparatus comprising a phase lock loop (PLL) and a lock circuit. The PLL may be configured to multiply an input frequency in response to a lock signal. The lock circuit may be configured to generate the lock signal. The PLL may also be configured to select a reference frequency as (i) the input frequency when in a first mode and (ii) a divided frequency of the input frequency when in a second mode.

Method for phase locking in a phase lock loop

An electronic circuit, such as the type which may be found in a watch pager receiver, which contains both analog and digital circuitry, includes harmonic noise minimization circuitry. The minimization circuitry is constructed using standard cell designs which are optimized for particular clock operations. Select circuit components are optimized to produce minimal harmonics, to operate at the predetermined frequency and include resistance means to provide an output of a second known level which is characterized by an optimized output signal having a ramped wave configuration. The optimized output signal is of adequate strength to provide an input to a downstream component.

Harmonic noise minimization in a radio receiver by selectively

A microcircuit bias-current supply in a wristwatch-pager. An FM-radio receiver in a microcircuit paging device operates intermittently with a short on-time and long off-time to reduce power consumption and preserve battery life. The bias-supply circuit distributes predetermined bias currents to a plurality of functional circuit areas of the microcircuit die, the bias currents being disabled during off-time of the receiver such that the current drain of the entire microcircuit is virtually zero, being in the range of nanoamps. The inefficiencies and disadvantages of a series switch to stitch power on and off are eliminated by providing a plurality of switched current sources which perform the dual function of circuit biasing and current switching.

Combined bias supply and power shut-off circuit with selective biasing

A microcircuit bias-current supply in a wristwatch-pager. An FM-radio receiver in a microcircuit paging device operates intermittently with a short on-time and long off-time to reduce power consumption and preserve battery life. Ths bias-supply circuit distributes predetermined bias currents to a plurality of functional circuit areas of the microcircuit die, the bias currents being disabled during off-time of the receiver such that the current drain of the entire microcircuit is virtually zero, being in the range of nanoamps. The inefficiencies and disadvantages of a series switch to switch power on and off are eliminated by providing a plurality of switched current sources which perform the dual function of circuit biasing and current switching.

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Tigard, OR, United States of America

Russell R Moen