摘要:
Digitally controllable ICs or function blocks in an electronic apparatus are connected through control bus lines, and a switch device is provided for disconnecting one of the digitally controllable ICs or function blocks from the control bus so that the control bus is not disabled when that one IC is turned off or is not occupied when the IC is operating in its internal processing mode. Therefore, communication between the remaining ICs can be maintained through the control bus.
摘要:
A control system for an electronic apparatus, such as a television receiver, having a control circuit with a control program in an internal memory sequentially communicates over an internal bus within predetermined intervals, such as within the vertical blanking interval of the television signal, with a plurality of controllable circuits in the television receiver, and the control circuit operates to select and communicate with a specific, selected one of the controllable circuits first, in each predetermined interval, with the remainder of the controllable circuits being subsequently communicated with in the remaining portion of the vertical blanking interval.
摘要:
Digital data transfer in a digital television receiver between an internal central processing unit, or an external computer, and the video/audio processing circuitry by way of an internal bus is accomplished efficiently and without producing noise interference by using a high-frequency clock signal and a relatively low-frequency clock signal at different times. The high-frequency signal would normally produce visually perceptable noise, however, it is employed only during vertical blanking intervals, and the low-frequency clock signal, which would not produce visually perceptable noise, is used at all times other than the vertical blanking intervals, whereby noise interference that would be otherwise seen on the visual display of the television receiver is suppressed.
摘要:
First and second counters in a pulse width modulating circuit, whose respective outputs determine the trailing and leading edges of a pulse width modulated signal, count input clock pulses at a constant speed. The number of the pulses applied to the second counter during a cycle relative to the number of the pulses applied to the first counter is increased or decreased by one in response to a modulating pulse to change the counting phase of the second counter thereby changing the width of the pulse width modulated signal. Gates freeze the phases of the two counters at minimum and maximum pulse widths of the pulse width modulated signal to avoid abrupt jumps from minimum to maximum or vice versa.
摘要:
A digital control system for electronic apparatus employs an internal bus system and includes at least one master controller and a plurality of operational circuits connected via control bus lines so that, during normal operation of the electronic apparatus, the master controller can carry out predetermined control operations relative to the respective circuit blocks. During testing and/or adjustment, an auxiliary master control circuit is connected to the control bus lines in order to control the operational circuitry in place of the master control circuit, while holding the master control in the slave mode.
摘要:
A system for controlling electronic apparatus, such as a television receiver, which employs a control circuit having a control program in a read only memory to sequentially communicate over an internal system bus in a predetermined interval with a plurality of controllable, operational circuit blocks forming the electronic apparatus, in which the control circuit selects a specific circuit block for data transfer upon a request signal. In one embodiment, a request signal is transmitted prior to a vertical blanking interval in a television signal and in another embodiment, a dedicated line is provided from a selected controllable unit to the control unit, whereby the request signal can be transmitted at any time, irrespective of whether data is being transferred at such time.
摘要:
An arrangement and a method for testing various kinds of electronic equipment, each having an internal bus, during assembly and during subsequent servicing, wherein a plurality of software packages, each storing instructions and data pertinent to the testing and adjustment of a specific kind of equipment are prepared and a computer is connectable in common to the various kinds of equipment via their internal buses for testing any one of the various equipments according to the contents of the appropriate software package.
摘要:
This invention relates to an apparatus for descrambling scrambled television signals including a scrambled video signal having a first scrambling pattern, a scrambled control signal having a second scrambling pattern, and descrambling signals.
摘要:
A color information display apparatus includes a common memory of an integrated circuit configuration for storing both pattern data and color data describing an attribute of the corresponding pattern data to be displayed on a CRT, the common memory including a first address area for the pattern data and a second, different address area for the color data, a circuit for generating address signals for the common memories in response to the scanning position of the electron beam on the screen of the CRT, a parallel-serial converting circuit for converting parallel pattern data in the common memory to serial data, a first latch circuit for latching the color data in the common memory to produce an output color signal, a circuit for generating a color information signal from the serial data from the parallel-serial converting circuit and the output signal from the first latch circuit, an address selector connected between the address signal generating circuit and the common memory, the first address area and the second address area of the common memory being addressed alternatively by the address selector, and a second latch circuit connected between the common memory and the serial-parallel converting circuit for latching the pattern data supplied to the latter circuit.
摘要:
An AFT circuit for a television receiver automatically adjusts the frequency of a tuner local oscillator, not only on the basis of an error signal provided from an AFT discriminator, but also on the basis of horizontal synchronizing pulses contained in the video signal to which the receiver is tuned. A synch signal detector detects the presence or absence of the synchronizing pulses. A control circuit provides a control signal to the local oscillator in response to the AFT error signal when the latter is above or below a reference voltage such that the desired frequency is within an AFT capture range. However, when the AFT signal is at the reference voltage, the control circuit provides the control signal based on the presence or absence of the synchronizing pulses, such that when the pulses are present, the local oscillator frequency is raised, but when the pulses are absent, the local oscillator frequency is lowered. Then, when the AFT signal is present, the local oscillator is controlled thereby. This AFT circuit has an expanded effective capture range, and is prevented from locking onto the sound carrier of an adjacent channel. 00202