SH7280 Datasheet, PDF (1016/1726 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine family

Section 20 A/D Converter (ADC)
20.4 Operation
The A/D converter has two operating modes: single-cycle scan mode and continuous scan mode.
In single-cycle scan mode, A/D conversion is performed once on one or more specified channels
and then it ends. In continuous scan mode, the A/D conversion is performed sequentially on one or
more specified channels until the ADST bit is cleared to 0.
The ADCS bit in the A/D control register (ADCR) is used to select the operating mode. Setting
the ADCS bit to 0 selects single-cycle scan mode and setting the ADCS bit to 1 selects continuous
scan mode. In both modes, A/D conversion starts on the channel with the lowest number in the
analog input channels selected by the A/D analog input channel select register (ADANSR) from
AN0 to AN3.
In single-cycle scan mode, when one cycle of A/D conversion on all specified channels is
completed, the ADF bit in ADSR is set to 1 and the ADST bit is automatically cleared to 0. In
continuous scan mode, when conversion on all specified channels is completed, the ADF bit in
ADSR is set to 1. To stop A/D conversion, write 0 to the ADST bit. When the ADF bit is set to 1,
if the ADIE bit in ADCR is set to 1, an A/D conversion end interrupt (ADI) is generated. When
clearing the ADF bit to 0, read the ADF bit while set to 1 and then write 0. However, when the
DMAC or DTC is activated by an ADI interrupt, the ADF bit is automatically cleared to 0.
Rev. 1.00 Jun. 26, 2008 Page 986 of 1692
REJ09B0393-0100