摘要:
A method and apparatus is provided for testing the logic functionality and electrical continuity of a ring oscillator comprising an odd number of inverters connected to form a closed loop. In the method and apparatus, a known value is forced through the ring oscillator, to test the complete circuit path thereof. Thus, a low overhead deterministic test of the functionality of the ring oscillator is provided. In a useful embodiment of the invention, a method is provided for testing functionality and electrical continuity in a ring oscillator, wherein a first test device is inserted between the input of a first inverter and the output of an adjacent second inverter. The first test device is then operated to apply first and second test bits as input test signals to the first inverter input. The embodiment further comprises detecting the response to the applied first and second test bit signals at the output of the second inverter, and using the detected responses in providing an evaluation of functionality of the ring oscillator.
摘要:
A circuit topology which can be used to create an array of individually tuned oscillators operating at different frequencies determined by common control inputs and an easily managed variation in design dimensions of several components is provided. An array of oscillators are provided arranged in columns and rows. Each oscillator in a column is unique from the other oscillators in the column based on number of stages in the oscillator and fanout so that each oscillator will operate at a unique frequency. Oscillators of different columns within the array may differ by a common setting of the selects to these oscillators and the physical ordering of the oscillators in the column to further reduce the possibility of injection locking. A base delay cell provides selects to each column of oscillators such that each column may be programmed to operate at a different frequency from its neighbors.
摘要:
A random number generator, a method, and a computer program product are provided for producing a random number seed. Each oscillator within an array of oscillators operates at a different frequency. The operating frequencies of each oscillator are not harmonically related, such that no integer multiple exists between the frequencies of any two oscillators. In one embodiment, the outputs of the array of oscillators connect to a multiple input latch. The multiple input latch also receives a sample signal, which is a clock signal. The clock signal samples the outputs of the array of oscillators, and the multiple input latch in conjunction with the random number determination logic (“RNDL”) produces a digital output (0 or 1) for each oscillator within the array. The RNDL uses these digital outputs to create a random number seed.
摘要:
An apparatus and method for extracting a maximum pulse width of a pulse width limiter are provided. The apparatus and method of the illustrative embodiments performs such extraction using a circuit that is configured to eliminate the majority of the delay cells utilized in the circuit arrangement described in commonly assigned and co-pending U.S. patent application Ser. No. 11/109,090 (hereafter referred to as the '090 application). The elimination of these delay cells is made possible in one illustrative embodiment by replacing an OR gate in the circuit configuration of the '090 application with an edge triggered re-settable latch. The replacement of the OR gate with the edge triggered re-settable latch reduces the amount of chip area used in addition to the power consumption of the circuit.
摘要:
A method, an apparatus, and a computer program are provided for the semi-automatic extraction of an ideality factor of a diode. Traditionally, current/voltage curves for diodes, which provided a basis for extrapolating the ideality factors, had to be determined by hand. By employing a thermal voltage proportional to absolute temperature (PTAT) generator in conjunction with an extraction mechanism, the ideality factor can be extracted in an semi-automatic manner. Therefore, a reliable, quick, and less expensive device can be employed to improve measurements of ideality factors.
摘要:
An apparatus and method for automatically calibrating a duty cycle circuit for maximum performance are provided. A chip level built-in circuit that automatically calibrates the duty cycle correction (DCC) circuit setting for each chip is provided. This chip level built-in circuit includes a clock generation macro unit, a simple duty cycle correction (DCC) circuit, an array slice and built-in self test unit, and a DCC circuit controller. Results of a built-in self test, i.e. pass or fail, of an array are provided to the DCC circuit controller. If the result of the built-in self test is a pass, then the current DCC circuit controller's DCC control bit setting is set as the setting for the chip. If the result from the built-in self test is a fail, the DCC circuit controller's DCC control bits setting is incremented to a next setting and the self-test is performed again.
摘要:
The present invention provides for a method for characterization of pulse-width limiter outputs. A known clock signal is received. A pulse width of the received known clock signal is limited through a first pulse-width limiter to generate a first intermediate signal. The first intermediate signal is delayed by a known amount to generate a first delayed signal. The first intermediate signal is inverted to generate a first inverted signal. A pulse width of the first inverted signal is limited through a second pulse-width limiter to generate a second intermediate signal. The second intermediate signal is delayed by a known amount to generate a second delayed signal. A logic OR operation is performed on the first delayed signal and the second delayed signal to generate a clock out signal.
摘要:
The present invention provides for a low pass filter. A first capacitor, has a first associated leakage current. A second capacitor has a specified capacitance that is a fraction of the capacitance of the first capacitor, the second capacitor further having a second associated leakage current. A voltage follower circuit is coupled to the output of the first and second capacitor. First and second current sources are coupled to the voltage follower circuit. A bias current source is coupled the first current source. A current mirror is coupled to the second current source, and the current mirror is further coupled to at least the anode of the first capacitor, thereby generating replacement current of a capacitor within a low-pass filter.
摘要:
A method, an apparatus, and a computer program are provided to measure and/or correct duty cycles. Duty cycles of various signals, specifically clocking signals, are important. However, measurement of very high frequency signals, off-chip, and in a laboratory environment can be very difficult and present numerous problems. To combat problems associated with making off-chip measurements and adjustments of signal duty cycles, comparisons are made between input signals and divided input signals that allow for easy measurement and adjustment of on-chip signals, including clocking signals.
摘要:
The present invention provides a method, an apparatus, and a computer program product for measuring the temperature of a microprocessor through the use of ESD circuitry. The present invention uses diodes and an I/O pad within ESD circuits to determine the temperature at the location of the ESD circuitry. First, a current measuring device connects to a diode. A user or a computer program disables the protected component or circuitry, and subsequently applies a predetermined voltage to the I/O pad. This creates a reverse saturation current through the diode, which is measured by the current measuring device. From this current the user or a computer program determines the temperature of the microprocessor at the diode through the use of a graphical representation of diode reverse saturation current and corresponding temperature.