| 摘要 |
PURPOSE: To fast and easily perform the timing check regardless of the number of commands or the number of patterns changing for each command by providing a parity check means which decides whether the operation timings of control signals of plural types have errors or not. CONSTITUTION: A parity generator 20 is connected to the connection wiring parts 11-1, 11-2, 11-3 and 11-4 which are branched out from an output signal wiring 3 and corresponding to the signals RAS, CAS, WE and CS respectively. Then the generator 20 generates the parities based on the change of each timing of those parts 11-1 to 11-4 and temporarily stores these parities in a parity storage part 21. Then the parities are inputted to a parity checker 22. The parities outputted from the generator 20 are compared with the operation timings of control signals of several types right before they are inputted to a RAM 12. Thus it is decided whether the operation timings of control signals have errors or not. |
