| 摘要 |
PURPOSE:To shorten an analyzing time of a C1 coverage index showing whether a branch instruction is executed exactly or not, by designating the range in which a designated branch instruction is contained, in a program containing plural branch instructions. CONSTITUTION:A CPU1 executes a branch instruction when it goes to a fetch cycle, and outputs a fetch data FD. This data FD is decoded by an instruction decoder 2, sets an FF3, and also opens an AND gate 5 through an OR gate 4. An AND gate 5 receives a timing signal from a controlling circuit 8 and registers 9 the timing signal. Accordingly, an address data stored in a buffer register 6 in accordance with the branch instruction is stored in the register 9. A delaying circuit 7 delays the timing signal by 1 CPU cycle, resets the FF3, and closes the AND gate 5 through the OR gate 4. In case when the data of the register 9 exists between data of comparing circuits 10, 11, and AND gate 14 is opened, and a gate 15 is opened. In this way, a test is executed exactly. |
