Operation; Scanning Operation - Renesas RX100 Series User Manual

RX13T Group
26.3

Operation

26.3.1

Scanning Operation

In scanning, A/D conversion is performed sequentially on the analog inputs of the specified channels.
A scan conversion is performed in three operating modes: single scan mode, continuous scan mode, and group scan
mode. In single scan mode, one or more specified channels are scanned once. In continuous scan mode, one or more
specified channels are scanned repeatedly until the ADCSR.ADST bit is cleared to 0 from 1 by software. In group scan
mode, the selected channels of groups A, B, and C are scanned once after starting to be scanned according to the
respective synchronous trigger.
In single scan mode and continuous scan mode, A/D conversion is performed for ANn channels selected by the
ADANSA0 register, starting from the channel with the smallest number n. In group scan mode, A/D conversion is
performed for ANn channels of groups A, B, and C selected by the ADANSA0 register, ADANSB0 register, and
ADANSC0 register, respectively, starting from the channel with the smallest number n.
When self-diagnosis is selected, it is executed once at the beginning of each scan and one of the three voltages internally
generated in the 12-bit A/D converter is converted.
Double trigger mode is to be used with single scan mode or group scan mode. With double trigger mode being enabled,
A/D conversion data of a channel selected by the ADCSR.DBLANS[4:0] bits is duplicated only if the conversion is
started by the synchronous trigger selected by the ADSTRGR.TRSA[5:0] bits. In group scan mode, the double trigger
function can be used only for group A.
Extended double trigger mode indicates a state when the following synchronous trigger (two synchronous trigger sources
enabled) is selected by the TRSA[5:0] bits in the A/D conversion start trigger select register (ADSTRGR) in double
trigger mode.
 TRG4AN or TRG4BN (the ADSTRGR.TRSA[5:0] bits are set to 001011b)
In extended double trigger mode, in addition to normal operations in double trigger mode, A/D conversion data is stored
in A/D data duplication register A (ADDBLDRA) or A/D data duplication register B (ADDBLDRB) depending on the
trigger type. If two types of triggers have occurred simultaneously in this mode, A/D conversion data is not sorted by the
trigger sources and is stored in data duplication register B (ADDBLDRB).
Note that if a new trigger is input during A/D conversion caused by another trigger, the new trigger is ignored.
When any of AN000 to AN002 channels is set as a channel-dedicated sample-and-hold circuit by the
S12AD.ADSHCR.SHANS[2:0] bits, the target analog input is sampled and held before the first A/D conversion of each
scan.
The ADST0 output is used to output the S12AD.ADCSR.ADST bit state
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
26. 12-Bit A/D Converter (S12ADF)
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