| 摘要 |
PURPOSE:To constitute a flexible system and to reduce the capacity of a control memory circuit by transferring the contents of an erasable read-only memory circuit to the control memory circuit and operating it as a read/write memory. CONSTITUTION:When a firmware control instruction 1 from an address n+2 of the read-only memory circuit 1 is decoded by a data correcting and copying means 7, the contents of the read-only memory circuit 1 are erased according to a copy word counter P. Then, one-word data is read out of an address (n+2)+P+1 of the read-only memory circuit 1 by the data correcting and copying means 7 and written in an address m+2 of the control memory circuit 3. Further, a firmware control instruction 2 is read out of an address (n+2)+P+2 of the read-only memory circuit 1 by the data correcting and copying means 7 and decoded and then it is processed as an instruction NOP by a control switch circuit 8. Thus, an indication is sent out of the control switch circuit 8 to alter the contents of the control memory circuit 3. |
