| 摘要 |
PURPOSE:To easily perform the external control by providing a monitor ROM where specific instructions are stored and control bits are provided. CONSTITUTION:A NOP instruction which executes nothing, a jump (JMP) instruction, a transfer instruction group for internal register read, and a transfer instruction group for internal register write are stored in an output instruction part (INSTRUCTION) of a monitor ROM 1. Control bit parts M0 to M3 of the monitor ROM 1 are connected to a latch 2. The latch output M0 controls reset of a program counter 12. The output M1 controls selection of the instruction part of the monitor ROM 1 and an address register 11 at the time of execution of the JMP instruction in the monitor ROM 1. Outputs M2 and M3 control a flip flop 7. Thus, only address designation of the monitor ROM 1 is fundamentally performed as the control from the outside to realize the debugging function. |
