| 摘要 |
PURPOSE:To more flexibly set up the sampling frequency of an A/D converter through software control by allowing a system body circuit to periodically accessing data outputted from the A/D converter by its own timing control. CONSTITUTION:When the system body circuit 1 accesses a control circuit 2 in order to obtain digital data, the circuit 2 decodes address data passed through an address bus 5 by its inner decoder circuit 22 and inputs the decoded data to the A/D converter 3 as a sample start signal. The access to the circuit 2 is controlled by software incorporated in the body 1 and periodically executed to set up sampling frequency. Namely, the sampling of the A/D converter 3 is started synchronously with access to data outputted from the converter 3 and the sampling frequency is set up by controlling the access so as to periodically access the data by the software incorporated in the circuit 1. |
