| 摘要 |
PURPOSE:To facilitate the memory diagnosis by using a bit rewriting register to hold a check bit to be given and reading out the check bits outputted from an error check collection circuit and said rewriting register and written into a memory circuit to use these check bits. CONSTITUTION:In a normal action mode an ECC circuit 1 produces a check bit for the data to be written into a memory 2 and writes the data 2-1 and the bit 2-2. When a check mechanism is diagnosed, a new check bit 2-2 to be written into the memory 2 is previously stored in a check bit writing register 3 via a CPU. Then the circuit 1 reads out those data 2-1 and bit 2-2 to carry out a checking task. Then a pseudo memory error generating signal obtained later is read out by the CPU for execution of the diagnosis of a memory check function. |
