Operation Modes And Trigger Modes - NEC PD703114 User Manual

11.6.2 Operation modes and trigger modes

Diverse conversion operations can be specified for A/D converters 0 and 1 by specifying the operation mode and
trigger mode. The operation mode and trigger mode are set using the ADSCM00 or ADSCM10 register.
The relationship between the operation mode and the trigger mode is shown below.
Trigger Mode
AD trigger
AD trigger polling
Timer trigger
External trigger
(1) Trigger modes
Four trigger modes that serve as the start timing of A/D conversion processing are available: A/D trigger
mode, A/D trigger polling mode, timer trigger mode, and external trigger mode.
These trigger modes are set using the ADSCM00 and ADSCM10 registers.
(a) A/D trigger mode
A/D trigger mode, which starts the conversion timing for the analog input set for the ANI0m or ANI1n pin
(m = 0 to 5, n = 0 to 7), is a mode in which A/D conversion is started by setting the ADCE0 or ADCE1 bit
of the ADSCM00 or ADSCM10 register to 1. In this mode, it is necessary to set the ADCE0 or ADCE1 bit
to 1 as an A/D conversion restart operation after the INTAD0 or INTAD1 interrupt (ADCS0, ADCS1 = 0).
(b) A/D trigger polling mode
A/D trigger polling mode, which starts the conversion timing of the analog input set for the ANI0m or
ANI1n pin (m = 0 to 5, n = 0 to 7), is a mode in which A/D conversion is started by setting the ADCE0 or
ADCE1 bit of the ADSCM00 or ADSCM10 register to 1. In this mode, it is not necessary to set the
ADCE0 or ADCE1 bit to 1 as an A/D conversion restart operation after the INTAD0 or INTAD1 interrupt
(ADCS0, ADCS1 = 1). The specified analog input is converted serially until the ADCE0 or ADCE1 bit is
set to 0. The INTAD0 or INTAD1 interrupt occurs each time a conversion ends.
(c) Timer trigger mode
Timer trigger mode, which starts the conversion timing of the analog input set for the ANI0m or ANI1n pin
(m = 0 to 5, n = 0 to 7), is a mode governed by the trigger specified by the A/D internal trigger selection
registers 0 and 1 (ITRG0, ITRG1).
(d) External trigger mode
External trigger mode, which starts the conversion timing of the analog input set using the ANI0m and
ANI1n pins, is a mode specified using the ADTRG0 or ADTRG1 pin (m = 0 to 5, n = 0 to 7).
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CHAPTER 11 A/D CONVERTER
Operation Mode
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User's Manual U15195EJ5V0UD
Setting
ADSCM00
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ADSCM10