摘要:
A data modulation interface is provided for serial data transmission. A biphase signal is encoded with the binary bits of a parallel data word. The bits of the parallel data word are examined to determine whether there are more one bits or zero bits in the word. A polarity bit is provided in addition to the other bits to indicate which bit-state occurred most often. The biphase signal is modulated to create different time intervals between phase reversals with one time interval corresponding to a bit-state of one and another time interval corresponding to a bit-state of zero. The shortest time interval is assigned to correspond to the bit-state occurring most often in the word so that the total time required to transmit each word is minimized. A time interval can be assigned to a sync signal transmitted after each parallel data word. A time interval can also be assigned to correspond to plural bit combinations so they can be represented by a single phase interval and transmitted quickly.
摘要:
Ein Bussystem für einen seriellen Datenbus enthält eine Datenbitquelle (1), an deren Datenausgang (2) eine einzige Busleitung (3) angeschlossen ist. Eine Datenbitserie besteht aus einem Startbit und einer bestimmten Anzahl Datenbits: das Startbit mit einer fallenden Flanke, die Datenbits mit einer ansteigenden Flanke. Den Bitwert eines Datenbits kennzeichnet die Länge des Impulses, mit dem das Datenbit beginnt. Ein Befehlsdecoder (4) tastet jedes Datenbit mit einem in einer bestimmten Zählerstellung (z8) erzeugten Abtastimpuls eines Taktimpulszählers (10) ab, der von den Impulsen einer Taktimpulsquelle (11) fortgeschaltet wird und von einem Flankendetektor (12) gesteuert wird. Die zu den Abtastzeitpunkten in einen Datenbitspeicher (18) eingeschriebenen Datenbitwerte werden am Ende der Datenbitserie in einen Befehlsspeicher (20) in dem gespeicherten Befehl entsprechende Steuersignale (S7) umgesetzt. Für die Taktimpulsfrequenz der Taktimpulsquelle (11) ist keine hohe Genauigkeit erforderlich.
摘要:
A variable oscillator, suitable for integration as part of a phase lock loop (PLL) clock source in a complementary metal oxide semiconductor (CMOS) integrated circuit, includes an amplifier and terminals for connection to a a tank circuit, for example a crystal resonator. A passive reactance is alternately coupled and decoupled in relation to the amplifier to cause oscillatory operation at lower and higher frequencies. In the CMOS circuit the reactance is conveniently provided by conductive layers of predetermined dimensions being carried by an oxide layer. Each layer provides a capacitive reactance which is arranged in series with a field effect defice being controlled by associated PLL control circuitry.
摘要:
Binary data is transmitted as signals of two different pulsewidths to respectively represent logic "0" or "1 ". At the data receiver the ratio of the pulsewidths is converted into a corresponding voltage ratio, which, in turn, is applied through a voltage divider to develop clock- and data-control signals at two different levels. Switching devices are respectively actuated whenever the clock- and data-control signals reach preset voltage levels to respectively produce self-synchronized clock and data pulses corresponding to the received binary data.
摘要:
Binary data is transmitted as signals of two different pulsewidths to respectively represent logic "0" or "1 ". At the data receiver the ratio of the pulsewidths is converted into a corresponding voltage ratio, which, in turn, is applied through a voltage divider to develop clock- and data-control signals at two different levels. Switching devices are respectively actuated whenever the clock- and data-control signals reach preset voltage levels to respectively produce self-synchronized clock and data pulses corresponding to the received binary data.
摘要:
Le procédé de transmission de message sous forme codée binaire, en mode série asynchrone entre modules émetteurs récepteurs autonomes possédant des horloges et des dispotifs de synchronisation internes indépendants, s'applique à une organisation dans laquelle les modules sont reliés entre eux par une seule ligne de transmission. Le procédé selon l'invention consiste à appliquer sur la ligne de transmission une suite de signaux correspondant chacun à un état 0 ou 1 d'un digit du message à transmettre. Chaque signal a une durée déterminée fonction de l'état Z = 0 ou U = 1 du digit transmise. La reconnaissance par le récepteur de la suite des 0 ou des 1 du message transmis est effectuée par la mesure de la durée Z/E et U/E des signaux reçus à l'aide de la durée d'un signal étalon E transmis en même temps que le message par l'émetteur. L'invention s'applique notamment à la réalisation des fonctions électriques d'un véhicule automobile.
摘要:
A decoder circuit for decoding phase-encoded digital data signals includes a timing circuit and a signal viewer circuit coupled to logic circuitry. The timing circuit uses an edge of a received phase-encoded digital data signal to indicate when to sample data from the received phase-encoded digital data signal in the signal viewer circuit. The logic circuitry determines the value encoded in the phase-encoded digital data signal based on the sampled data.
摘要:
A self initialized coder and method thereof, the coder arranged and constructed for decoding an information stream (217), the coder including a buffer (301) for storing a portion (403) of the information stream, a controller (313) coupled to the buffer (301) for temporally reversing a first part (401) of the portion to provide a file header (415), and an adaptive decoder (213) having a state parameter, the adaptive decoder (213) coupled to the controller (313) and the buffer (301), for decoding the file header (415) to provide an estimate of the state parameter and thereafter for decoding, using the estimate, the portion (403) to provide a decoded signal.
摘要:
A demodulator for a pulse width modulated signal comprises a counter arranged to count in one direction when the PWM signal is "high" and in the opposite direction when the PWM signal is "low" to arrive at a count representative of a duty cycle. As a result, a value representative of the duty ratio of the PWM signal can be obtained from the up/down counter. In a further embodiment, the up/down counter is clocked by the output of a frequency multiplier, the output of the frequency multiplier having a frequency determined by the pulse width modulated signal frequency multiplied by a predetermined factor. The value of the duty ratio of the PWM signal can then be found regardless of the frequency of the PWM signal.