| 摘要 |
<p>PURPOSE:To use a program by correcting the bug of the program incorporated in ROM after the production of a microcomputer. CONSTITUTION:An instruction executing part 5 reads the address of the bug and a corrected program from a memory 14 by way of a serial interface 10 and respectively stores them in a register 9 and RAM 4. When the execution address of the program reaches the address of the bug, data of a program counter 1 is equal to the data of the register 9 so that a comparing part 6 outputs a selection signal 12 and a selection circuit 7 selects a branch instruction generating circuit 8 to provide a branch instruction to the instruction executing part 5. Thus, the instruction executing part 5 executes the branch instruction to execute it to a program after correction stored in RAM 4 by branching.</p> |
