| 摘要 |
PURPOSE:To know surely and easily if A/D conversion function is normal by a CPU, by checking an A/D conversion value to a reference voltage via a multiplexer and an A/D converter through the CPU. CONSTITUTION:When a CPU1 needs analog data, an input switching signal and a conversion instruction are respectively transmitted to a decoder 5 and a delay circuit 7 from the CPU1. An input switching signal is inputted to a multiplexer 6 from the decoder 5, analog data AD1-ADn are selectively outputted, and A/D converted at an A/D converter 4 based on the conversion instruction via the delay circuit 7 and fetched to a CPU1 as digital data DD. On the other hand, a reference voltage from a reference voltage generator 8 is added to the analog data AD1-ADn and the A/D-converted values are checked. |
