摘要:
A multi-bit Read Only Memory (ROM) cell has a semiconductor substrate of a first conductivity type with a first concentration. A first and second regions of a second conductivity type spaced apart from one another are in the substrate. A channel is between the first and second regions. The channel has three portions, a first portion, a second portion and a third portion. A gate is spaced apart and is insulated from at least the second portion of the channel. The ROM cell has one of a plurality of N possible states, where N is greater than 2. The possible states of the ROM cell are determined by the existence or absence of extensions or halos that are formed in the first portion of the channel and adjacent to the first region and/or in the third portion of the channel adjacent to the second region. These extensions and halos are formed at the same time that extensions or halos are formed in MOS transistors in other parts of the integrated circuit device, thereby reducing cost.
摘要:
The present invention is a storage element for controlling a logic circuit and a logic device having a plurality of storage elements. The storage element has a first and a second non-volatile memory cells connected in series at an output node Each of the first and second non-volatile memory cells is for storing a state opposite to the other. A multiplexer has an input, a switched input and two outputs. The output node is connected to the input of the multiplexer. One of the outputs is used to control the logic circuit. The other output is connected to a bit line which is connected to a sense amplifier. Finally, the switched input receives a switch signal and outputs the signal from the output node to either the one output or the other output.
摘要:
A array of multi-bit Read Only Memory (ROM) cells is in a semiconductor substrate of a first conductivity type with a first concentration. Each ROM cell has a first and second regions of a second conductivity type spaced apart from one another in the substrate. A channel is between the first and second regions. The channel has three portions, a first portion, a second portion and a third portion. A gate is spaced apart and is insulated from at least the second portion of the channel. Each ROM cell has one of a plurality of N possible states, where N is greater than 2. The state of each ROM cell is determined by the existence or absence of extensions or halos that are formed in the first portion of the channel and adjacent to the first region and/or in the third portion of the channel adjacent to the second region. These extensions and halos are formed at the same time that extensions or halos are formed in MOS transistors in other parts of the integrated circuit device, thereby reducing cost. The array of ROM cells are arranged in a plurality of rows and columns, with ROM cells in the same row having their gates connected together. ROM cells in the same column have the first regions connected in a common first column, and second regions connected in common second column. Finally, ROM cells in adjacent columns to one side share a common first column, and cells in adjacent columns to another side share a common second column.
摘要:
The present invention is a storage element for controlling a logic circuit and a logic device having a plurality of storage elements. The storage element has a first and a second non-volatile memory cells connected in series at an output node. Each of the first and second non-volatile memory cells is for storing a state opposite to the other. A demultiplexer has an input, a switched input and two outputs. The output node is connected to the input of the demultiplexer. One of the outputs is used to control the logic circuit. The other output is connected to a bit line which is connected to a sense amplifier. Finally, the switched input receives a switch signal and outputs the signal from the output node to either the one output or the other output.
摘要:
A array of multi-bit Read Only Memory (ROM) cells is in a semiconductor substrate of a first conductivity type with a first concentration. Each ROM cell has a first and second regions of a second conductivity type spaced apart from one another in the substrate. A channel is between the first and second regions. The channel has three portions, a first portion, a second portion and a third portion. A gate is spaced apart and is insulated from at least the second portion of the channel. Each ROM cell has one of a plurality of N possible states, where N is greater than 2. The state of each ROM cell is determined by the existence or absence of extensions or halos that are formed in the first portion of the channel and adjacent to the first region and/or in the third portion of the channel adjacent to the second region. These extensions and halos are formed at the same time that extensions or halos are formed in MOS transistors in other parts of the integrated circuit device, thereby reducing cost. The array of ROM cells are arranged in a plurality of rows and columns, with ROM cells in the same row having their gates connected together. ROM cells in the same column have the first regions connected in a common first column, and second regions connected in common second column. Finally, ROM cells in adjacent columns to one side share a common first column, and cells in adjacent columns to another side share a common second column.
摘要:
A nonvolatile reprogrammable switch for use in a PLD or FPGA has a nonvolatile memory cell connected to the gate of an MOS transistor with the terminals of the MOS transistor connected to the source of the signal and to the circuit. The nonvolatile memory cell is of a split gate type having a first region and a second region, with a channel therebetween. The cell has a floating gate positioned over a first portion of the channel, which is adjacent to the first region and a control gate positioned over a second portion of the channel, which is adjacent to the second region. The second region is connected to the gate of the MOS transistor. The cell is programmed by injecting electrons from the channel onto the floating gate by hot electron injection mechanism. The cell is erased by Fowler-Nordheim tunneling of the electrons from the floating gate to the control gate. As a result, no high voltage is ever applied to the second region during program or erase. In addition a MOS FET transistor connects the gate of the MOS transistor to a voltage when the non-volatile memory cell is turned off. The floating gate of the non-volatile memory cell is connected to the gate of the MOS FET transistor.
摘要:
A nonvolatile reprogrammable switch for use in a PLD or FPGA has a nonvolatile memory cell connected to the gate of an MOS transistor with the terminals of the MOS transistor connected to the source of the signal and to the circuit. The nonvolatile memory cell is of a split gate type having a floating gate positioned over a first portion of the channel and a control gate positioned over a second portion of the channel with electrons being injected onto the floating gate by hot electron injection mechanism. The nonvolatile memory cell is erased by the action of the electrons from the floating gate being tunneled through Fowler-Nordheim tunneling onto the control gate, which is adjacent to the second region. As a result, no high voltage is ever applied to the second region during program or erase. Thus, the nonvolatile memory cell with the second region can be connected directly to the gate of the MOS transistor, which together therewith forms a nonvolatile reprogrammable switch.