| 摘要 |
<p>PURPOSE:To reduce the burden on a microcomputer itself by forming an interrupt signal after discriminating that input signals reach a conversion level within a preset range. CONSTITUTION:Input analog signals are held by a register 2 after the signals are converted into digital signals in a conversion circuit 1. A comparator circuit 4 compares the content of the register 2 with the content of an upper-limit setting register 31 and, when the content of the register 2 is smaller, sets '1' to a flag 51. The circuit 4 successively compares the content of the register 2 with the content of s lower-limit setting register 32 and, when the content of the register 2 is larger, sets '0' to a flag 52. When the contents of the flags 51 and 52 are respectively '1' and '0', it is discriminated that the level of the input analog signals is within a preset range and an interruption circuit 6 generates an interrupt signal to a microcomputer. Therefore, it is not required to discriminate the results of A/D conversion every time and the processing burden of the hardware and software of the microcomputer can be reduced.</p> |
