| 摘要 |
PURPOSE:To enable using for log out in a module such as LSI etc. by forming a shift ring circuit connected only to a shift register latch to be logged out when executing log out. CONSTITUTION:When log out is performed by occurrence of an error, clock of a terminal C1 is stopped, a terminal S1 is set to 1, and clock A and clock B are applied from terminals A1 and B1 respectively. Accordingly, only the first shift ring circuit 12 is shifted out from a terminal So1. At this time, terminals A, B, S of shift register latches 5G, 5H etc. connected to the second shift ring circuit 15 are 0, and normal clock from a terminal C2 does not stop. Accordingly, these shift register latches 5G, 5H etc. continue normal operation. Thus, a shift ring circuit that is connected only to a shift register latche to be logged out when executing log out during system operation is formed. |
