| 摘要 |
PURPOSE:To improve the reliability of a large-scale integrated LSI circuit by extracting only the output of one of a pair of cells functioning simultaneously to the outside of the LSI circuit and then using the output of the other cell when an error is detected with the first cell. CONSTITUTION:An LSI circuit consists of a mode register MR, the 1st control circuit FC, cells E1-E4 having equivalent functions or processing capacities and stored in a unit circuit containing an error detecting means and the 2nd control circuit SC. The same data D310 and D330 are supplied to cells E1/E2 and E3/E4 via switches X3-X5 of the circuit FC and switches X6 and X7 of the circuit SC respectively. These two pairs of cells function simultaneously. The mode signal MS applied to the register MR sets cells E1 and E3 under an active state and cells E2 and E4 under a waiting state respectively. The switches X8 and X9 of the circuit SC receive data D41 and D43 from cells E1 and E3 and deliver them to the outside of the LSI circuit as data D410 and D420. When an error is detected with the cell E1 or E3, error signals A1 and A3 are transmitted for changeover of the signal MS. Then the outputs of cells E2 and E4 are extracted outside. |
