| 摘要 |
PURPOSE: To externally monitor data inside a RAM without using any external bus and further to externally monitor the data inside the RAM without occupying any internal bus of a CPU by providing a specified real-time debugger(RTD). CONSTITUTION: First and second emulation ROM (emROM) 61 and 62 are memories having the same address and equal capacity and only one of them is accessed from a CPU 103. When the emROM to be used for the CPU 103 is made switchable, an RTD 1A can access the other emROM without affecting the operation of the CPU 103 for access to the emROM. Therefore, while the CPU 103 uses one emROM, the RTD 1A changes the contents of the other emROM and after the contents are changed, the emROM to be used for the CPU 103 can be switched. Namely, a program can be changed while the CPU 103 is operated. |
