Renesas rl78 User Manual

Page of 1004
 
RL78/G1A 
 
CHAPTER  11   A/D  CONVERTER 
R01UH0305EJ0200  Rev.2.00 
 
 
380  
Jul 04, 2013 
11.6.9  Hardware trigger wait mode (select mode, sequential conversion mode) 
 
<1>  In the stop status, the ADCE bit of A/D converter mode register 0 (ADM0) is set to 1, and the system enters the 
hardware trigger standby status. 
<2>  If a hardware trigger is input while in the hardware trigger standby status, A/D conversion is performed on the 
analog input specified by the analog input channel specification register (ADS).  The ADCS bit of the ADM0 
register is automatically set to 1 according to the hardware trigger input. 
<3>  When A/D conversion ends, the conversion result is stored in the A/D conversion result register (ADCR, ADCRH), 
and the A/D conversion end interrupt request signal (INTAD) is generated.  After A/D conversion ends, the next 
A/D conversion immediately starts.  (At this time, no hardware trigger is necessary.) 
<4>  If a hardware trigger is input during conversion operation, the current A/D conversion is interrupted, and 
conversion restarts.  The partially converted data is discarded. 
<5>  When the value of the ADS register is rewritten or overwritten during conversion operation, the current A/D 
conversion is interrupted, and A/D conversion is performed on the analog input respecified by the ADS register.  
The partially converted data is discarded. 
<6>  When ADCS is overwritten with 1 during conversion operation, the current A/D conversion is interrupted, and 
conversion restarts.  The partially converted data is discarded. 
<7>  When ADCS is cleared to 0 during conversion operation, the current A/D conversion is interrupted, the system 
enters the hardware trigger standby status, and the A/D converter enters the stop status.  When ADCE = 0, 
inputting a hardware trigger is ignored and A/D conversion does not start. 
 
Figure 11-25.  Example of Hardware Trigger Wait Mode (Select Mode, Sequential Conversion Mode)  
Operation Timing 
 
ADCE is set to 1.
<1>
A hardware trigger 
is generated.
<2>
A hardware trigger is 
generated during A/D 
conversion operation.
<4>
A/D conversion ends 
and the next 
conversion 
starts.
<3>
ADS is rewritten during 
A/D conversion operation 
(from ANI0 to ANI1).
<5>
Conversion is 
interrupted 
and restarts.
Conversion is 
interrupted 
and restarts.
Conversion is 
interrupted and 
restarts.
<3>
<3>
<3>
<3>
ADCS is overwritten 
with 1 during A/D 
conversion operation.
<6>
ADCS is cleared 
to 0 during A/D 
conversion operation.
ADCE
ADCS
ADS
INTAD
ADCR,
ADCRH
A/D
conversion
status
Hardware
trigger
Stop status
ANI0
ANI1
The trigger
is not
acknowledged.
Trigger
standby
status
Trigger
standby
status
The trigger
is not
acknowledged.
Data 1
(ANI0)
Data 1
(ANI0)
Data 2
(ANI0)
Data 4
(ANI0)
Data 2
(ANI0)
Data 3
(ANI0)
Data 4
(ANI0)
Data 5
(ANI0)
Data 6
(ANI1)
Data 6
(ANI1)
Data 8
(ANI1)
Data 7
(ANI1)
Data 8
(ANI1)
Data 9
(ANI1)
Stop status
Conversion is
interrupted.
<7>