upd70f3402 Renesas Electronics Corporation., upd70f3402 Datasheet - Page 382

• Manufacturer Part Number: upd70f3402
• Description: 32-/16-bit Single-chip Microcontroller With Can Interface
• Manufacturer: Renesas Electronics Corporation.

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Software trigger mode
The following trigger modes that serve as the start timing of A/D conversion processing are
available: A/D trigger mode and polling mode.
These trigger modes are set using the ADSCM0H register.
(a) A/D trigger mode
In this mode, the A/D conversion is started by setting bit CE of A/D conversion mode register 0
(ADSCM0H) to 1.
To restart the A/D conversion after the INTAD interrupt (A/D conversion completed; CS bit =”0”),
the CE bit has to be set again to start the next conversion.
If registers ADSCM0H, ADSCM0L, and ADSCM1H are written to during conversion, conversion
stops and starts over from the beginning.
(b) Polling mode
In this mode, the A/D conversion is started by setting bit CE of A/D conversion mode register 0
(ADSCM0H) to 1.
Unless the CE bit is set to 0 following conversion, the next conversion operation is performed.
When conversion starts, the CS bit becomes 1 (operation in progress).
If registers ADSCM0H, ADSCM0L, and ADSCM1H are written to during conversion, conversion
stops and starts over from the beginning.
External trigger mode
In this mode, conversion is started by the input of an external trigger. External trigger rising edge
detection of the ADTRG input pin, or by interrupt signal output from Timer P2 can be specified with
bits TRG0 and TRG1 of the ADSCM0H register.
In this mode, setting bit CE of the ADSCM0H register to 1 causes the trigger standby state to be
entered, and conversion starts upon input of an external trigger. Upon completion of conversion,
the state changes back to the trigger standby state.
When conversion starts, the CS bit becomes 1 (operation in progress). In the trigger standby state,
the CS bit is 0 (operation stopped).
Upon input of a valid trigger during conversion, the conversion operation stops and starts over
from the beginning.
If registers ADSCM0H, ADSCM0L, and ADSCM1H are written to during conversion, conversion
stops and starts over from the beginning.
User’s Manual U16702EE3V2UD00
Chapter 11 A/D Converter