| 摘要 |
PURPOSE:To effectively use a limited storage capacity and to confirm the flow of the entire program, by selecting and storing specified information only out of the information produced when the instruction designated with a program is executed. CONSTITUTION:First, a step trace mode is set to a mode selecting circuit 4 with a mode set signal 12, step value data 11 are set to an instruction counter 5 and a step trace mode completion address is set to an address register 6. In executing the trace program, the counter 5 is counted up with a control signal 9 and a fetch signal 10 to generate a trace enable signal 13, an address count-up signal 8 is inputted to a mode selecting circuit 4 and applied to an address advance signal to an address generator 2. As a result, the information of a CPU16 is written in a trace memory 1, and when the content of the register 6 and the address 15 from the CPU16 are coincident, a mode switching signal 14 is outputted from a coincidence detection circuit 17 to the circuit 4 and the mode is switched to the normal full trace mode. |
