| 摘要 |
PURPOSE:To facilitate an easy test of plural ROMs with small hard quantity, by providing a test address generating circuit, a horizontal parity calculating circuit, a horizontal parity deciding information storage circuit and a comparator respectively. CONSTITUTION:In the test operation modes of ROM1-1-1-n, a check address generating circuit 2 generates check addresses for test successively and feeds them to each ROM as well as to horizontal parity deciding information storage circuit 4. The output data of each ROM is supplied to a horizontal parity calculating circuit 5 for calculation of the horizontal parity. The horizontal parity is previously stored in the circuit 4 to the check address and compared with the calculated parity information to decide the correctness of reading. In such a way, it is possible to test plural ROMs with small hard quantity. |
