| 摘要 |
PURPOSE:To read out the content of a register without stopping a clock signal by providing a register group started by external or internal events for holding the content, a select circuit for selecting the content of the register group, and a shift register. CONSTITUTION:A control part 5 decodes a diagnostic command, and outputs a register hold instruction 102 and a counter control signal 103. The registers 11-14 hold or release the respective contents according to an instruction 102 from the control part 5. The instruction 102 is output by decoding a command 101, and also output by an event (e.g. occurrence of failure) generated in the interior of a LSI. The select circuit 2 selects one of the registers 11-14 according to a select signal 104 output by a counter 3. Output signals of the selected registers 11-14 are converted to serial data by a shift register 4 and output as read-out data 105. |
