A/D converter and a microcontroller including the same
In an A/D converter and a microcontroller including the same, the number of selection patterns of analog input channels is increased for each A/D conversion and the A/D conversion is conducted using an A/D converter having only fundamental functions without imposing load onto a CPU. The A/D converter or a DMA transfer device includes an A/D conversion table including one or more entries. Each entry includes enable bits for setting whether or not an A/D conversion is executed for the respective analog input channels and a plurality of count number bits for setting a number of executions of the A/D conversion.
1. A microcontroller, comprising:
a memory;
an analog-to-digital (A/D) converter comprising a plurality of analog input channels; and
a direct memory access (DMA) transfer device for transferring a result of an A/D conversion from the A/D converter to the memory, wherein:
said DMA transfer device comprises an A/D conversion table for setting an analog input channel for an A/D conversion;
when an A/D conversion is indicated, said DMA transfer device refers to the A/D conversion table to initiate an A/D conversion of the A/D converter; and
when the A/D conversion is finished, said DMA transfer device transfers a result of the conversion from the A/D converter to the memory.
2. A microcontroller according to claim 1 , wherein
said A/D converter comprises:
a control register for setting an analog input channel for an A/D conversion; and
a DMA request signal for requesting the DMA transfer device to conduct a DMA transfer;
the DMA transfer device sets the analog input channel to the control register of the A/D converter to thereby initiate an A/D conversion; and
when the A/D converter outputs the DMA request signal after the A/D conversion is finished, said DMA transfer starts a DMA transfer.