Operation In External Trigger Mode; Operation In Select Mode - NEC PD703114 User Manual

V850e/ia2 32-bit single-chip microcontrollers

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11.10 Operation in External Trigger Mode

In external trigger mode, an analog input (ANI00 to ANI05, ANI10 to ANI17) is A/D converted at the ADTRG0 or

ADTRG1 pin input timing.

The valid edge of an external input signal in external trigger mode can be specified as the rising edge, falling edge,

or both rising and falling edges using the ES21 or ES20 bit of the INTM1 register for A/D converter 0 and the ES31 or

ES30 bit of the INTM1 register for A/D converter 1.

One analog input (ANI00 to ANI05, ANI10 to ANI17) specified by the ADSCM00 or ADSCM10 register is A/D

converted. The conversion result is stored in the ADCR0m or ADCR1n register (m = 0 to 5, n = 0 to 7).

Using the ADTRG0 or ADTRG1 signal as a trigger, one analog input is A/D converted at a time and the result is

stored in the ADCR0m or ADCR1n register.

registers. For each A/D conversion, an A/D conversion end interrupt (INTAD0 or INTAD1) is generated, which

terminates A/D conversion (ADCS0, ADCS1 bit = 0).

ADTRGm signal

n: 0 to 5 when m = 0, or 0 to 7 when m = 1

To restart A/D conversion, a trigger must be input again from the ADTRGn pin (n = 0, 1).

This is optimal for applications that read results each time there is an A/D conversion in synchronization with an

external trigger.

Figure 11-12. Example of Select Mode (External Trigger Select) Operation (ANI02): For A/D Converter 0

(1) ADCE0 bit of ADSCM00 = 1 (Enabled)

(2) External trigger generation

(3) A/D conversion of ANI02

(4) Store conversion result in ADCR02

(5) INTAD0 interrupt generation

CHAPTER 11 A/D CONVERTER

Analog inputs correspond one-to-one with A/D conversion result

Analog Input

A/D converter 0

User's Manual U15195EJ5V0UD

A/D Conversion Result Register