| 摘要 |
<p>PURPOSE:To obtain the highly reliable microcomputer of high-speed microprogram system by turning on between a scan register disposed opposite an output circuit putting a memory array in between and the respective data lines of the memory array only at time testing. CONSTITUTION:A switch means DSW which is turned on only in the test mode is provided between the scan register DSR having serial-parallel conversion function and the respective data lines of the memory array M-ARY. A normal read action from a microprogram ROM is executed without employing the scan register DSR. During the time other than testing time, the scan register DSR and the data lines are separated and the load on the data lines accordingly is reduced. Therefore, a normal read action from the microprogram ROM can be speeded up.</p> |
