Patent GB-1529842-A (GB)
Title: Digital data stores and data storage systems
IPC: H04N7/088
Filed: 1975-10-09
Abstract: 1529842 Digital data storage systems TEXAS INSTRUMENTS Ltd 9 Oct 1975 41425/75 Heading G4A A digital data store for storing input data comprising a plurality of blocks of information digits, each block being associated with a respective group of two-part address digits consisting of a page address and a row address, comprises decoding means 2 associated with a plurality of serially accessed registers 1A-1X arranged to store data, each register being independently addressable via an associated respective first switching means 3A-3X to write data into the data store and via an associated respective second switching means 4A-4X to read data out of the data store, the first and second switching means being controlled by the decoding means 2, each group of two-part address digits being uniquely related to a respective preselected register and being used to route input data to the appropriate register, data being extracted from the data store by commands which locate the required register, and each register being identified by a preselected page address and by a rowwithin a page address. As shown, the decoding means 2 decodes row addresses for register selection, but in an alternative embodiment, Fig. 2 (not shown) the decoding means comprises an incrementing shift register (12) which addresses the registers sequentially, data being written into an addressed register if the data row address corresponds with the register row address. If the two row addresses do not correspond, e.g. for an out-of-sequence input row, the incrementing shift register is not clocked and the out-of-sequence input row is lost. The incrementing shift register is then clocked by two pulses and writing into the data store continued, it being assumed that input rows are normally in correct row sequence. Codes relating the preselected registers to the groups of two-part address digits may be manually preselectable by means of a keyboard, time codes being optionally appended so that data bearing a desired time code is stored. The serially accessed registers may consist of a plurality of dynamic storage devices such as charge coupled devices or magnetic bubble devices, in which case the bits of each digit are stored in parallel. The outputs of the data store may be fed to any one of a plurality of recirculating shift register stores (107-109), Figs. 5, 6 (not shown), each of which shift register stores may store a page of data whereas the data store stores only a single page of data. The output of any one of the shift register stores may be fed back to the data store. This arrangement may be used for storing pages of information which are transmitted between frames of a television signal, the arrangement then forming part of a broadcast television receiver. The outputs of the data store may be used to feed the C.R.T. of such a receiver without the need for an intermediate buffer store, since data in any row of the data store may be recirculated (for readout to produce a number of scan lines on the C.R.T.) without interference with any other row of the data store. Recirculation of the rows of the data store during line blanking periods need not be inhibited if phantom characters are stored to provide a suitable gap between the finish of one row and the start of the next. Such a data storage system is similar to that of Specification 1,526,232 which is referred to. A plurality of identical data stores may be connected in parallel to provide storage for, e.g., 32 pages of data, the decoding means of each data store being programmed to recognize a respective specific page address.