| 摘要 |
PURPOSE:To prevent an incorrect card from being selected even when a noise is mixed, by employing three kinds of guard: the coincidence of select signals, that of check bits, and the presence/absence of a control signal. CONSTITUTION:When a card 2 is selected, a data signal 1b is outputted to an external device from a controller 1 via a data output apparatus 2e only when an address signal 1a from the controller 1 coincides with the select signal 1e proper to the card 2, and also, a check bit signal generated at a check bit generator 2b coincidences with a check bit signal 1c generated at the controller 1, and also, the control signal 1d from the controller 1 is generated. |
