| 摘要 |
A memory has a plurality of memory cells that each store a voltage signal indicative of a multiple bit signal. Each logic value of the multiple bit signal has a unique voltage range. The voltage ranges are unequal and are selected so that the decay of the voltage of the voltage signal in the range remains in the range for each level at a predetermined time. This memory provides logic levels so that the decay time of the voltage signal is greater for larger voltages of the voltage signal. The decay time in each logic level is almost equal. A voltage generator provides the voltage signal to the memory cells responsive to a multiple bit digital data signal. The voltage generator may include a digital-to-analog converter that provides the voltage signal and has at least one more bit than the multiple bit digital data signal. A memory stores a lookup table and provides another multiple bit data signal to the digital-to-analog converter responsive to the multiple bit digital data signal. Alternatively, the digital-to-analog converter may have resistors of different resistances to generate the voltage signal nonlinearly relative to the multiple bit digital data signal. Alternatively, the digital-to-analog converter has a nonlinear device, such as a diode, to generate the voltage signal nonlinearly relative to the multiple bit digital data signal.
|
