Datasheet

Table Of Contents
Section 20 A/D Converter
Rev. 2.00 Jul. 04, 2007 Page 447 of 692
REJ09B0309-0200
20.4.2 External Trigger Input Timing
The A/D converter can also start A/D conversion by input of an external trigger signal. External
trigger input is enabled at the ADTRG pin when the ADTSTCHG bit in PMRB is set to 1* and
TRGE bit in AMR is set to 1. Then when the input signal edge designated in the ADTRGNEG bit
in IEGR is detected at the ADTRG pin, the ADSF bit in ADSR will be set to 1, starting A/D
conversion.
Figure 20.2 shows the timing.
Note: * The ADTRG input pin is shared with the TEST pin. Therefore when the pin is used as
the ADTRG pin, reset should be cleared while the 0-fixed or 1-fixed signal is input to
the TEST pin. Then the ADTSTCHG bit should be set to 1 after the TEST signal is
fixed.
φ
ADTRG
(when
ADTRGNEG = 0)
ADSF
A/D conversion
Figure 20.2 External Trigger Input Timing
20.4.3 Operating States of A/D Converter
Table 20.2 shows the operating states of the A/D converter.
Table 20.2 Operating States of A/D Converter
Operating
Mode
Reset
Active
Sleep
Watch
Sub-
active
Sub-
sleep
Standby
Module
Standby
AMR Reset Functioning Functioning Retained Retained Retained Retained Retained
ADSR Reset Functioning Functioning Retained Retained Retained Retained Retained
ADRR Retained* Functioning Functioning Retained Retained Retained Retained Retained
Note: * Undefined at a power-on reset.