摘要:
A high speed full adder circuit is shown to include logic circuitry responsive to the levels of the two digital signals to be added for: (a) immediately producing an appropriate carry signal when the levels of the digital signals are the same; and (b) inverting the carry signal into such adder when the levels of the digital signals differ.
摘要:
A content limit addressable memory (CLAM) having a plurality of lower and upper limits stored therein for comparison to corresponding subfields of an input word. Each corresponding upper and lower limit forms a bracket. Corresponding brackets form a window. The brackets correspond to the subfields and are of the same number of bits. The brackets and subfields are alterable in width to allow each bracket and subfield to have any number of bits in multiples of two. A valid match of the input word with any window can occur with any combination of the brackets of a window matching or not matching the corresponding subfields of the input word. A plurality of outputs corresponding to each of the windows indicates a match of the corresponding window to the input word. Additionally, the CLAM can compare data stored therein against an applied window with the matching operations as described above.
摘要:
A multibit digital adder is shown wherein a pair of carry generating circuitries is disposed between single adders for each bit in the digital numbers to be added, each one of such carry generating circuitries being responsive to a different carry-in signal and to the level of the bits applied to the associated single bit adder to produce the proper carry-in signal to the following single bit adder.
摘要:
A non-volatile integrated circuit memory is provided having an array of memory elements selectively programmable to store complimentary binary data, each one of such memory elements being formed in a different region of the integrated circuit and having an address terminal, an output terminal, a ground terminal, and a power supply terminal. Those memory cells programmed into a first logical state are provided with transistor action between the output terminal and the power supply terminal and are inhibited from having transistor action between the output terminal and the ground terminal. Conversely, those memory cells programmed to store the complementary logic state are inhibited from having transistor action between the output terminal and the power supply terminal and are provided with transistor action between the ground terminal and the output terminal. In either programmed state, the transistor action is controlled by signals fed to the address terminal of the cells. With such arrangement, since transistor action is prevented between the power supply terminal and the ground terminal of each cell, an electrical open-circuit is always present to the power supply with the result that a precharge cycle is not required during memory addressing to reduce power. The elimination of such pre-charge cycle thereby eliminates the time delays inherent with the precharge cycle circuitry to thereby increase the operating speed of the memory and, further, the elimination of the circuitry increases the storage capacity of the ROM by making more chip area available for memory cells.
摘要:
An integrated circuit memory having a plurality of row lines; a plurality of select lines; a plurality of output lines; a plurality of memory cells; each pair of memory cells having common outputs coupled to a select one of the plurality of output lines and common address inputs coupled to a select one of the plurality of row lines, wherein ambiguity of which memory cell of the pair of memory cells to be selected, being coupled to a select one of the plurality of row lines and a select one of the plurality of output lines, is determined by two selected ones of the plurality of select lines coupled thereto. Also provided is a first decoder, responsive to an input address, for enabling a select one of the plurality of row lines, and a second decoder, responsive to the row lines and to the input address, for enabling a select one of the select lines which corresponds to pairs of memory cells with an enabled row line.
摘要:
A memory cell of the general type employing one pair of IGFETs defining data nodes and cross-coupled in a latch circuit configuration for storing data, and another pair of IGFETs serving as transmission gates to selectively couple data into or out of the cell. A circuit technique provides fast writing speed by avoiding the use of load resistors in either the charge or discharge paths for the data nodes and yet ensures that the data nodes are pulled either fully to logic high or fully to logic low, as the case may be, without limitation by threshold voltage offset between the gate and source terminals of the IGFETs serving as transmission gates. High impedance leakage current discharge resistances are included, and serve only the function of discharging leakage at the nodes to maintain memory. In the disposed circuit configurations, the latch IGFETs are of opposite channel conductivity type compared to the gating IGFETs. Various alternative forms of suitable high impedance leakage current resistances are disclosed, including a resistive sea above the cell and leakage paths included within the gating IGFETs. The high impedance leakage current discharge resistances may be eliminated to provide a dynamic memory cell.
摘要:
A five-transistor CMOS static latch cell useful in static flip-flop applications comprises, in one embodiment, an inverting latch cell having a data input node, a data storage node, a complementary data output node, a clock input node for selectively enabling or not enabling the cell, and a pair of voltage supply nodes. An essentially standard CMOS inverter has an output connected to the complementary data output node. The inverter includes a complementary pair of IGFETs i.e., an N-channel IGFET and a P-channel IGFET. The channel of the N-channel inverter IGFET selectively electrically connects the complementary data output node to ground. The channel of the P-channel inverter IGFET selectively electrically connects the complementary data output node to the voltage supply node. The inverter transistor gate electrodes are connected to the data storage node. A cross-coupled switching element comprising a second P-channel IGFET has its gate connected to the complementary data output node and is arranged to selectively connect the data storage node to the voltage supply node. A third P-channel IGFET has its channel arranged to selectively connect the data storage node to the voltage supply node when the cell is disabled. A second N-channel IGFET is arranged to selectively connect the data storage node to the data input node. A high impedance leakage current discharge path electrically connects the data storage node to the one voltage supply node, and discharges any leakage current on the data storage node. The high impedance leakage current discharge path may take a variety of forms, and need not comprise a discrete resistor.
摘要:
A shift register using dual gate transistors is described. Each stage consists of a P-channel and and N-channel dual gate transistor interconnected to provide both an inverting function and a switching function. The gates of each stage of one set of alternate stages are clocked in one phase with a clocking voltage alternating between a low level and a high level and its inverse. The gates of each stage of the other set of alternative stages are clocked in the opposite phase with the clocking voltage and its inverse.
摘要:
The ROM utilizes a diode x-y memory array which can be comprised of a number of suitable materials which form rectifying junctions. The diodes are formed vertically in order to provide a very high density array. On pitch decoder circuitry which is capable of matching the high density of the memory cells in the x-y memory array is also described, as is a unique apparatus for joining adjacent ends of conductive lines which are spaced very close together without increasing their pitch.