| 摘要 |
PURPOSE:To enable an output part to read out the memory information on the address designated by the external address information, by writing previously the control information permitting an external reading action to the prescribed address of an information rewriting part. CONSTITUTION:When a built-in ROM 115 is read out in a normal state, an address decoder 200 is designated by an address designating line 106 and then one of buffer parts 211-215 is designated by selection signal lines 102-205. When the contents of the ROM 115 are read out in a test mode, a buffer read line 207 is set at '1' with a valid read buffer 208 with the timing by which a read permitting information line 121 and a read pulse signal line 112 are set at '0' and '1' respectively with a test mode signal 102 set at '1'. Then a built-in ROM access control part 123 transfers the data on a read latch line 112-0 to a data transfer line 109-0. |
