摘要:
An operation of a CPU is defined by a predetermined clock. An image memory stores in or read-out image data to be displayed. A display controller connects between the CPU and the image memory, and receives a command from the CPU during an access period set by time-dividing a display period and for controlling a write or read operation of the image data with respect to the image memory. A timing signal generator generates a reference pulse for representing a relationship between the clock for defining the operation of the CPU and the access period. An operation state detector receives the reference pulse generated by the timing signal generator and an access control signal output from the CPU, and detects a state of the CPU with respect to the access period. A wait signal generator generates a wait signal to the CPU, in accordance with a detection result from the operation state detector.
摘要:
A memory control device which is able to interface with any memory regardless of the address information format for reading out data stored therein. The memory control device includes an address generator for generating address information for reading out corresponding data from the memory device, a data processing circuit such as a microprocessor for processing the stored data, a first bus for transmitting the stored data from the memory device to the data processing circuit, a second bus for transmitting address information generated by the address generator to the memory device, a third bus for selectively transmitting either the stored data to the data processing circuit or transmitting address data to the memory device, a mode signal generator for generating a mode signal, and a control circuit connected between the mode signal generator and the third bus for controlling the selective data transmission of the third bus in response to the mode signal.
摘要:
A raster scan image data display controller including a means for reducing flickering comprises an image memory for storing image data items at horizontal and vertical display addresses corresponding to horizontal and vertical coordinates on an image display area, a read-out device for supplying the horizontal and vertical display addresses to the image memory and reading out the image data items from the image memory, a display device for interlaced displaying of the read-out image data on paired scanning lines of two types of fields which are to be formed by a raster scan, a timing control device for synchronizing the horizontal and vertical display addresses with the raster scan of the display device, and a timing switching device for permitting said paired scanning lines of two types of fields formed by the raster scan in association with a timing control by the timing control device, to be switched, so as to select a pair of scanning lines which are situated close to each other.
摘要:
A decoder decodes digital color information data from an input section into a predetermined number of pieces of color information consisting of specific color information and specific luminance information. A first converter converts the specific luminance information of each of the predetermined number of pieces of color information into a digital luminance signal component. A second converter converts the two color difference signals uniquely defined by the relationship between the specific color information and the specific luminance information of each of the predetermined number of pieces of information into a digital color difference signal component. A modulator digitally performs balanced modulation for the two color subcarrier components having phases shifted by 90 degrees from a color subcarrier component generator by using the digital color difference signal components, and outputs digital carrier chrominance signal components. An adder adds the digital carrier chrominance signal components from the modulator and the digital luminance signal component, and outputs digital video signal components. A third converter converts the digital video signal components into an analog waveform and outputs an analog video signal.
摘要:
This invention relates to an image display system for reading out image data stored in an image memory and displaying the image data on multiple image planes and the vertical scrolling operation can be independently effected for each of the image planes displayed on the multiple image plane display basis. That is, assuming that two image planes are displayed on upper and lower areas, display starting addresses lying in the vertical direction of the upper and lower image planes and stored in registers are loaded into a counter via a switch in a display period of the upper and lower image planes to generate addresses in the vertical direction of the upper and lower image planes. The vertical scrolling operation only for one of the upper and lower image planes can be effected by sequentially updating the display starting addresses lying in the vertical direction of the upper and lower image planes and held in one of the registers.
摘要:
A divider circuit for dividing n-bit binary data L.sub.n by a number m which is defined as m=2.sup.a -1 (a is a positive integer of 2 or more), wherein a division operation L.sub.n /m is developed into an infinite series given as: ##EQU1## for L.sub.(n-ba) =L.sub.n /2.sup.ba (where b is a positive integer).The divider circuit includes a first circuit responsive to the binary data L.sub.n, for sectioning a decimal part of each term of the infinite series in a unit of a-bit from a most significant bit of the decimal part, and for summing corresponding a-bit sectioned portions of decimal parts of all terms of the infinite series to generate summed decimal parts, a second circuit for discriminating a carry to an integer part of the binary data L.sub.n from the summed decimal parts, and a third circuit for adding the carry to a sum of integer parts of the binary data L.sub.n to provide divided data corresponding to L.sub.n /m.
摘要:
A first 5-stage ring counter generates a signal having a frequency of (4/5)f.sub.SC by dividing a frequency 8f.sub.SC of a signal. A second 5-stage ring counter generates a signal having a frequency of (4/5)f.sub.SC by dividing a frequency of a signal obtained by inverting the signal of frequency 8f.sub.SC by an inverter. A first sampling pulse output circuit generates a first sampling pulse from an output signal from the first 5-stage ring counter. A second sampling pulse output circuit generates a second sampling pulse from an output signal from the second 5-stage ring counter. A phase correction circuit causes synchronization of the count operation of the first 5-stage ring counter with a clock run-in signal. This phase correction is performed by shifting the phase of the output from the first 5-stage ring counter in units of the period of the signal of frequency 8f.sub.SC. When this phase correction is completed, the output signal from the first 5-stage ring counter is synchronized with the clock run-in signal such that the output signal is delayed by between 0 and 35 nsec with respect to the phase of the clock run-in signal. A discrininator divides a range of 0 to 35 nsec into two discrimination periods of 17.5 nsec each. The discriminator then discriminates during which one of the two discrimination periods the output signal from the first 5-stage ring counter appears. The discriminator then controls a sampling pulse switching circuit in accordance with the discrimination result.
摘要:
In a videotex terminal system, image data has a code frame and a photo frame, and each of these frames includes dot pattern data, foreground color data, background color data, and flashing data. This type of image data can be simultaneously displayed on both a cathode ray tube display (CRT) and a liquid crystal display (LCD). These two displays are not controlled independently of each other; rather, they are controlled in association with each other by a display control unit to eliminate the need to use a complicated software program in a central processing unit (CPU) and to reduce the number of hardware components required by the system. The display control unit is particularly advantageous in that is can easily discriminate the code frame and the photo frame from each other, and it enables the system to execute a reliable display operation.
摘要:
A character data processor for a videotex or teletext system includes a microcomputer section, a self data processing unit and a read/write memory. A memory access period for the memory exists in one read/write cycle of character data packets. Data processing unit responds to a first pulse indicating the start of the memory access period and to a second pulse indicating the end of the memory access period. Data processing unit includes an address change circuit which stores initial address data and transfers address data stored therein to the memory according to a transfer pulse. The content of address data is changed by a change pulse. A data register relays data transferred between the microcomputer section and the memory. A generator circuit generates the transfer pulse, the change pulse and a clock pulse according to the generation of the first and second pulses and a detection signal. A detection circuit responds to prescribed data indicating the run length of character data. A detection circuit detects a number of times of data transfer between the microcomputer section and the memory according to the clock pulse, and generates the detection signal when the number of times of data transferring corresponds to the prescribed data.
摘要:
A predetermined display period is divided into a plurality of shorter display periods. Image data is stored in an image memory and read in accordance with a period for reading the data from the memory. An accessing period is also provided, and access to the memory is made when the addressing mode is being set in a mode register during the accessing period, whereby the data is displayed by raster scanning.