| 摘要 |
PURPOSE:To prevent malfunction due to the breakage of a control storage by providing a register which holds the border address between the control storage and an external storage and detecting writing to the control storage. CONSTITUTION:When a microcode stored in an instruction register 15 is a write instruction for a storage device 2, an address selector 13 selects an address register which holds an optional address of an external storage 202 and indicates the write address to the storage device 2 through an address line 101. At the same time, the contents of a data register 16 which holds data to be written in the storage device 2 are indicated as write data to the storage device 2 through a data line 104. The storage device 2 stores the write data in the indicated address with a write enable signal 102. Then when the microprogram is debugged, a microprogram controller 1 is stopped at an optional address with a stop instruction 150. |
