Abstract:
A digital signal processor is designed to execute variable-sized instructions that may include up to N elementary instruction codes. The processor comprises a memory program comprising I individually addressable, parallel-connected memory banks in which the codes of a program are recorded in an interlaced fashion, and a circuit for reading the program memory arranged to read a code in each of the I memory banks during a cycle for reading an instruction. A cycle for reading an instruction in the program memory includes reading a sequence of codes that includes the instruction code or codes to be read and can also include codes, belonging to a following instruction, that are filtered before the instruction is applied to execution units. The program memory of the digital signal processor does not include any no-operation type codes.
Abstract:
A filtering circuit includes circuits for delivering first and second ramp-shaped signals when a logic signal to be filtered changes values, and includes logic circuits each with a switching threshold, for receiving the ramp-shaped signals. A memory unit delivers an output signal having a first value when outputs of the logic circuits have a first pair of values, and delivers a second value when the outputs of the logic circuits have a second pair of values. The filtering circuit may be applied to the filtering of an external clock signal in serial type memory devices.
Abstract:
A microprocessor may be switchable between a normal mode and a test mode for performing a test program and may include a central processing unit (CPU) for saving contextual data in a stack of the microprocessor at the time of switching to the test mode. The CPU may deliver, at the beginning of the test program and on an input/output port, contextual data present in the stack beginning with the top of the stack. The CPU may also decrement a stack pointer by a value corresponding to a number of contextual data delivered.
Abstract:
A generator includes an oscillator for producing a clock signal from an N-bit control number. The oscillator includes a first group of cells, with each cell including at least one series connected inverter. A first selection circuit selects a variable number of the cells as a function of the most significant bits of the control number. The oscillator also includes a second group of cells, with each cell including at least one series connected inverter. A second selection circuit selects one of the cells as a function of the least significant bits of the control number. The selected cells of the first and second groups of cells are series connected to form a chain of inverters.
Abstract:
An amplifier includes an input stage with one or more input terminals for receiving a signal to be amplified, and an output terminal. An inverting gain stage includes an input terminal connected to the output terminal of the input stage, an output terminal for delivering an amplified signal, and a variable feedback resistor connected between the output terminal and input terminal thereof. The input stage is a transconductor stage biased by a current source. A transconductance thereof is set by a resistor of the current source so that the amplifier has a gain proportional to the product of the variable feedback resistor multiplied by the transconductance.
Abstract:
A method for storing pages of a teletext service, with at least one page being received by a storage circuit of a television receiver, is provided. The storage circuit includes a data memory for storing the at least one received page. The method includes extracting a reference number from the at least one received page, checking whether the at least one received page is a requested page, and evaluating contents of the data memory to decide whether the at least one received page is to be stored as a function of free space in the data memory and an importance of the at least one received page. The method also includes storing the at least one received page if it is decided that the at least one received page is to be stored.
Abstract:
A method for adjusting a duration of an internal timing signal in an integrated circuit with a value close to a typical value of the duration may include activating the internal timing signal in the integrated circuit and sequentially sending calibration values to an input of the integrated circuit. The expiration of the internal timing signal may determine the last calibration value received or being received, and the calibration data may be applied to a device for adjusting the duration of the internal timing signal.
Abstract:
The present invention relates to a method of vapor phase epitaxial deposition of silicon on a silicon substrate including areas containing dopants at high concentration among which is arsenic, while avoiding an autodoping of the epitaxial layer by arsenic, including the steps of performing a first thin epitaxial deposition, then an anneal; the conditions and the duration of the first epitaxial deposition and of the anneal being such that the arsenic diffusion length is much lower than the thickness of the layer formed in the first deposition; and performing a second epitaxial deposition for a chosen duration to obtain a desired total thickness.
Abstract:
Processes are provided for fabricating a substrate having a silicon-on-insulator (SOI) or silicon-on-nothing (SON) architecture, which are applicable to the manufacture of semiconductor devices, especially transistors such as those of the MOS, CMOS, BICMOS, and HCMOS types. In the fabrication processes, a multilayer stack is grown on a substrate by non-selective full-wafer epitaxy. The multilayer stack includes a silicon layer on a Ge or SiGe layer. Active regions are defined and masked, and insulating pads are formed so as to be located around the perimeter of each of the active regions at predetermined intervals and placed against the sidewalls of the active regions. The insulating trenches are etched, and the SiGe or Ge layer is laterally etched so as to form an empty tunnel under the silicon layer. The trenches are filled with a dielectric. In the case of an SOI archiutecture, the tunnel is filled with a dielectric.
Abstract:
A method of determining the time for polishing the surface of an integrated circuit wafer on a polishing machine. A sample wafer is fabricated to include at least one high plateau and at least one low plateau joined by a sudden transition. At least one initial profile is topographically scanned, and the surface of the sample wafer is polished at a particular polishing pressure for a particular polishing time. The final profile of the polished layer is topographically scanned in the corresponding area, and the initial and final topographical scans of the sample wafer are converted into Fourier series. The surface of the wafer to be polished is topographically scanned, and the topographic scan of the wafer to be polished is converted into a Fourier series. The time for polishing the wafer to be polished is calculated from the Fourier series and the average thickness to be removed.