Word selection technique

摘要

997,869. Circuits employing bi-stable magnetic elements. THOMPSON RAMO WOOLDRIDGE Inc. July 30, 1963 [Aug. 2, 1962], No. 30231/63. Heading H3B. [Also in Division G4] In a word-organized memory, a word is selected by an arrangement comprising an array of switches connected respectively to the individual word lines, a single current source connected to all the switches being effective only via selected switch to energize the associated word line. A second array of switches may be provided, each word line being connected to a unique pair of switches, one from each array, Fig. 3. As described, a memory comprises four banks B1-B4 each containing 16 magnetic cores arranged in four word lines. The address of a required word in the memory is set up as four bits WXYZ (= 1101, as shown) in an address register 10, bits YZ selecting one of the four banks B1-B4 via a bank select switch array 20 and bits WX selecting one of the four word lines within a bank via a word select switch array 22. Fig. 4 shows the word select switch array 22 in more detail, the bank select switch array 20 being similar. The word select switch 22 comprises four cores 1-4 each having a bias winding 42; W and X switching windings 46, 44; a read winding 30 and write winding 32. In operation, assuming that the word address is 1101, word select core 4 and bank select core 4 will be switched via decoding matrices such as 34, thereby inducing a voltage in the read output winding 30 of word select core 4 to forward bias a diode 26 associated therewith. After a 0-2 Ás delay a current source I RS is energized to pass a read current I R through the selected word line to read out the selected word to a data register, Fig. 3. The data read out can be re-written when the word select core 4 and bank select core 4 are reset by the bias since diode 28 is then forward biased and if, after a 0À2 Ás delay, current source I ws is energized, a write current I w is passed along the selected word line to write the data stored in the data register, Fig. 3, into the cores of the selected word. In the same way fresh data can be written into the memory.