| 摘要 |
PURPOSE:To improve the efficiency of the program debug working, by tracing a block of the working contents of a microprocessor covering a range from a trigger point of a prescribed address through the next instruction. CONSTITUTION:When a microprocessor gives an access to a prescribed address, a trigger signal is fed to a control circuit 3. As a result, the output of an NOR gate 7 is set at L to set an address counter 2 under an enable state. In this case, an address and its contents of a prescribed area of a main storage device which are put on a bus 8 are written to an address designated by the counter 2 in a tracing memory 1. A series of actions to give an access to the prescribed address is over, and the next clock signal is fed to the circuit 3. Thus the output of the gate 7 is set at H, and the counter 2 is set under a disable state to discontinue the counting function. In such a way, a range from the trigger point of a prescribed address through the contents of the next instruction is defined as a block to be written successively to the memory 1 and then displayed on a CRT display device. |
