摘要:
A plurality of binary-to-decimal converters, logic gates and inverters provide a signal to a first output terminal when at least one error occurs in a data character, provide a signal to a second output terminal when only one error occurs in the character and provide a signal to a third output terminal when at least two errors occur in the character.
摘要:
A communications control apparatus prepares for the generation of an interrupt signal along with appropriate address signals to retrieve data information from the main memory store upon the request from the central processor. During preparation time, a tag directory is searched for an indication that the data information required is presently in the cache store. If a comparison is made, a match signal is generated to prevent the generation of the interrupt signal. The communications control apparatus addresses the cache store to retrieve the data information for use by the processor.
摘要:
A digital phase control adjustment system is provided for a d.c. motor which finds particular utility in applications where fast start and stop operations of the motor are required. The pulses forming a reference signal and those forming a variable signal are stored sequentially in a shift register and when the shift register is alternately storing ones and zeros, the pulses of the two signals are in alternate sequence for a certain number of periods, indicating that the motor speed is near the intended value.
摘要:
The power section of the switching regulator is divided into two identical parts. The two parts may be connected in series when a high value of power line voltage is used. The two parts are connected in parallel when a lower value of power line voltage is used. The same value of regulated output voltage may be obtained with either the series or the parallel connection.
摘要:
In a multiprocessor data processing system, all processors must have access to certain communications tables stored in the main memory shared by the processors. Each processor has a cache store embedded within for its individual use. A cache store in one processor might contain data from the communication tables which is obsoleted by operations of a second processor. The cache store clearing apparatus invalidates its data information any time its processor accesses the communication tables. The cache store is cleared by resetting tag directory indicators, a round robin counter and a column full flag, for each column in a four level set associative tag directory to the cache store. The data in the cache store need not be cleared. Using the four level set associative tag directory permits the data information in the cache store to be invalidated by a 16 pulse burst of signals for 1K words of cache store directed to the tag directory indicators.
摘要:
A digital processor includes: a main read only memory store providing instruction and constant data signals; a random access memory store for storing variable data signals; an input/output port unit communicating with the terminal devices; an interrupt address generator controlling the interrupt priority for the terminal devices; an arithmetic and logical unit; an instruction decoding and execution unit controlled according to instructions in a fast access read only memory store address controlled by the instruction signals in the main read only memory store for controlling the operations of the digital processor; and a group of working and general registers for buffer storage of digital signals. Interconnections between the units of the processor are through a single bidirectional data bus. Process steps control the operation of the processor according to an instruction format.
摘要:
A plurality of JK flip-flops, inverters and logic gates provide error signals when errors in phase occur between the phase bits and the data bits of information retrieved from a magnetic medium. The apparatus also provides warning signals when data bits are missing from the retrieved information.
摘要:
The sequencer employs a variable current source, a Schmidt trigger circuit, a one-shot, a pair of master-slave flip-flops and logic gates to provide pulses for operating a multiple switching regulator. A logic gate disables the sequencer to prevent the generation of pulses while a portion of the switching regulator is delivering current to an output terminal and thereby prevents possible damage to the switching regulator.
摘要:
Apparatus for detecting missing pulses in recovered NRZI encoded data. Positive and negative read signals are separated and applied to different error detecting circuits. Each error detecting circuit has a three stage, serial-transfer, shift register. The second stage output is connected to one circuit output terminal. The first and third stage outputs are applied to a conventional AND gate. The AND gate transmits an output pulse to the second circuit output terminal whenever the first and third stages contain logical ''''1''''s since the NRZI code dictates that an intermediate pulse of the opposite polarity must be missing. The circuit output terminals from both error detecting circuits are connected to the input of an OR gate.
摘要:
A system is disclosed in which an input binary address is transformed into a set of module select signals and a set of address signals whereby an aggregate of memory modules, each of which may contain a different number of storage cells, are combined to form a memory assembly which has a fixed number of storage cells. The address transformation system uses signals taken from the individual modules which represent the number of memory cells contained therein.