R01UH0822EJ0100 Rev.1.00
Page 877 of 1041
Jul 31, 2019
RX13T Group
26. 12-Bit A/D Converter (S12ADF)
26.3.9
Starting A/D Conversion with Asynchronous Trigger
The A/D conversion can be started by the input of an asynchronous trigger. To start up the A/D converter by an
asynchronous trigger, the A/D conversion start trigger select bits (ADSTRGR.TRSA[5:0]) should be set to 000000b, and
a high-level signal should be input to the asynchronous trigger (ADTRG0# pin). Then, the ADCSR.TRGE and
ADCSR.EXTRG bits should be set to 1.
shows a timing of the asynchronous trigger input.
For the time from when the ADST bit is set to 1 until conversion starts, refer to
section 26.6.3, A/D Conversion
Restarting Timing and Termination Timing
Figure 26.31
Timing of Sampling Asynchronous Trigger
26.3.10
Starting A/D Conversion with Synchronous Trigger from Peripheral Module
The A/D conversion can be started by a synchronous trigger. To start the A/D conversion by a synchronous trigger, the
ADCSR.TRGE bit should be set to 1, the ADCSR.EXTRG bit should be cleared to 0, and the relevant sources should be
selected by the ADSTRGR.TRSA[5:0] and ADSTRGR.TRSB[5:0] bits.
26.3.11
Programmable Gain Amplifier
A programmable gain amplifier is included in AN000 to AN002. Select the gain by setting the
S12AD.ADPGAGS.PnGAIN[3:0] bits (n = 000 to 002) for the AN000 to AN002 pins. Select the operational amplifier to
be used by setting the S12AD.ADPGACR.PnSEL1 bit (n = 000 to 002) for the AN000 to AN002 pins.
After setting the S12AD.ADPGACR.PnENAMP bit (n = 000 to 002) for the AN000 to AN002 pins to 1, wait for the
period for stabilizing of the programmable gain amplifier operation and set the ADCSR.ADST bit of the unit to 1.
Timing of sampling the asynchronous trigger
Asynchronous trigger
PCLK
ADST bit
4 states
Internal trigger signal