Renesas rl78 User Manual

 

RL78/G1A 

 

CHAPTER  11   A/D  CONVERTER 

R01UH0305EJ0200  Rev.2.00 

 

 

375  

Jul 04, 2013 

 

<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 

A/D conversion standby status. 

<2>  After the software counts up to the stabilization wait time

, the ADCS bit of the ADM0 register is set to 1 to 

perform A/D conversion on the four analog input channels specified by scan 0 to scan 3, which are specified by 

the analog input channel specification register (ADS).  A/D conversion is performed on the analog input channels 

in order, starting with that specified by scan 0. 

<3>  A/D conversion is sequentially performed on the four analog input channels, the conversion results are stored in 

the A/D conversion result register (ADCR, ADCRH) each time conversion ends, and the A/D conversion end 

interrupt request signal (INTAD) is generated. 

<4>  After A/D conversion of the four channels ends, the ADCS bit is automatically cleared to 0, and the system enters 

the A/D conversion standby status. 

<5>  When ADCS is overwritten with 1 during conversion operation, the current A/D conversion is interrupted, and 

conversion restarts at the first channel.  The partially converted data is discarded. 

<6>  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 first channel respecified by the ADS register.  

The partially converted data is discarded. 

<7>  When ADCS is cleared to 0 during conversion operation, the current A/D conversion is interrupted, and the 

system enters the A/D conversion standby status. 

<8>  When ADCE is cleared to 0 while in the A/D conversion standby status, the A/D converter enters the stop status.  

When ADCE = 0, specifying 1 for ADCS is ignored and A/D conversion does not start.  In addition, A/D 

conversion does not start even if a hardware trigger is input while in the A/D conversion standby status. 

 

Note  If a high-accuracy channel is selected as the analog input channel:  Stabilization wait time = 0.5 

μ

s 

If a standard channel is selected as the analog input channel: 

Stabilization wait time = 2 

μ

s 

 

 

ADCE

ADCS

ADS

INTAD

ADCR,

ADCRH

A/D

conversion

status

ADCE is set to 1.

<1>

The trigger

is not

acknowledged.

ADCS is set to 1 while 
in the conversion 
standby status.

<2>

Conversion

standby

Conversion

standby

Conversion

standby

Conversion

standby

Stop

status

Stop

status

Data 1
(ANI0)

Data 1
(ANI0)

Data 2
(ANI1)

Data 2
(ANI1)

Data 3
(ANI2)

Data 3
(ANI2)

Data 9
(ANI2)

Data 4
(ANI3)

Data 4
(ANI3)

Data 10

(ANI3)

Data 5
(ANI0)

Data 6
(ANI1)

Data 10

(ANI3)

Data 11

(ANI0)

Data 13

(ANI4)

Data 14

(ANI5)

Data 15

(ANI6)

Data 16

(ANI7)

Data 7
(ANI0)

Data 11

(ANI0)

Data 13

(ANI4)

Data 14

(ANI5)

Data 15

(ANI6)

Data 8
(ANI1)

Data 9
(ANI2)

Data 8
(ANI1)

Conversion is 
interrupted and restarts.

Conversion is 
interrupted and restarts.

<3>

ADCS is 
automatically 
cleared to 
0 after 
conversion 
ends.

<4>

ADCS is overwritten 
with 1 during A/D 
conversion operation.

<5>

<2>

<2>

<4>

Data 12

(ANI1)

Conversion is

interrupted.

ADCS is cleared 

to 0 during A/D 

conversion operation.

<7>

ADCE is cleared to 0. <8>

The trigger
is not
acknowledged.

A/D conversion
ends.

<3>

The interrupt is generated four times.

The interrupt is generated four times.

ADS is rewritten during 
A/D conversion operation.

<6>

ANI0 to ANI3

ANI4 to ANI7

Data 5 

(ANI0)

Data 7
(ANI0)