ANALOG RECORDING/REPRODUCING SYSTEM

摘要

PROBLEM TO BE SOLVED: To reduce the cost by applying an incremental step voltage to a flash memory cell to elevate the threshold voltage at each increment thereby programming a sampled analog signal in the flash memory cell by increment system. SOLUTION: A nonvolatile memory array 20 has a size of 1600 rows and 1200 columns wherein each cell stores a voice waveform for 125μS thus storing an analog signal, e.g. voice sampled at 8 kHz, for 240 sec. The array 20 divides a row into units of 200 cells and accesses a row address in 8 scans. 2000 column drivers are used in parallel in each scan in order to read/write a voice in units of 25 mS. A programming algorithm generates a constant incremental voltage pulse by 380 steps at a period of 62.5μS and compares the generated pulse with an inputted analog sample to determine a program voltage within 25 mS.