| 摘要 |
PURPOSE:To relieve a memory cell with a defects bit by inverting read data when addresses corresponding to the defective bit which are set by an address program without matches read address. CONSTITUTION:When the addresses A0R, A1R, A2R, and A3R which are set by the address program circuit I and correspond to the defective bit match the data read addresses A0, A1, A2, and A3, a coincidence detecting circuit II generates an output and a data inversion switching circuit III inverts data read out of the memory cell IV according to the data read addresses A0, A1, A2, and A3. When they do not coincide with each other, the coincidence detection circuit II generates no output and the read data are passed as they are. Thus, data read out of the defective bit are converted into correct data to relieve the defective memory cell. |
