CHAPTER 11 A/D CONVERTER
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User’s Manual U15195EJ5V0UD
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.
11.10.1 Operation in select mode
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. Analog inputs correspond one-to-one with A/D conversion result
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).
Trigger
Analog Input
A/D Conversion Result Register
ADTRGm signal
ANImn
ADCRmn
Remark
m = 0, 1
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
ANI00
ANI01
ANI02
ANI03
ANI04
ANI05
ADCR00
ADCR01
ADCR02
ADCR03
ADCR04
ADCR05
A/D converter 0
ADTRG0
(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
Содержание PD703114
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