| 摘要 |
PURPOSE:To attain an operation as a counter circuit or a pulse width modulation circuit by providing a means selecting whether two counter circuits are connected in series or the same counted pulse is inputted to both the counter circuits. CONSTITUTION:A changeover switch 11 selecting either the output terminal 7-2 of the n-th bit of the counter circuit 7 of the pre-stage or a counted pulse input terminal and connecting the selected result to the input terminal 8-1 of a counter circuit 8, and changeover circuits 12, 13 selecting either the n-th bit output terminal 7-2 of the pre-stage counter circuit 7 or the n-th bit output terminal 8-2 of the post-stage counter circuit 8 and inputting the selected result to an overflow detection circuit 14 are provided. When the position B of the switch 11 is selected, both the counter circuits 7, 8 count the same pulse input at every number counting set by a register 10, a TFF 15 is inverted and a pulse width modulation output is outputted. When the switch 11 is thrown to the position A, the entire circuit forms one counter circuit. |
