Renesas rl78 User Manual

 

RL78/G1A 

 

CHAPTER  11   A/D  CONVERTER 

R01UH0305EJ0200  Rev.2.00 

 

 

379  

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 

place the system in the hardware trigger standby status (and conversion does not start at this stage).  Note that, 

while in this status, A/D conversion does not start even if ADCS is set to 1. 

<3>  If a hardware trigger is input while ADCS = 1, A/D conversion is performed 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. 

<4>  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. 

<5>  After A/D conversion of the four channels ends, the ADCS bit remains set to 1, and the system enters the A/D 

conversion standby status. 

<6>  If a hardware trigger is input during conversion operation, the current A/D conversion is interrupted, and 

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

<7>  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. 

<8>  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. 

<9>  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.  However, the A/D converter does not stop in this status. 

<10> When ADCE is cleared to 0 while in the A/D conversion standby status, the A/D converter enters the stop status.  

When ADCS = 0, inputting a hardware trigger is ignored and A/D conversion does not start. 

 

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 

 

 

Trigger

standby

status

Conversion

standby

Stop

status

Stop

status

ADCE is set to 1.

<1>

ADCE

ADCS

ADS

INTAD

ADCR,

ADCRH

A/D

conversion

status

Hardware

trigger

ADCS is set to 1.

<2>

A hardware trigger 
is generated.

<3>

<3>

<3>

<3>

The trigger is not

acknowledged.

The interrupt is generated four times.

The interrupt is generated four times.

The interrupt is generated four times.

Conversion

standby

Conversion

standby

Conversion

standby

Conversion

standby

ADCS retains

the value 1.

<5>

<5>

<5>

<4>

A/D

conversion

ends.

Conversion is 
interrupted 
and restarts.

Conversion is 
interrupted 
and restarts.

Conversion is 
interrupted 
and restarts.

Conversion is

interrupted.

Data 1
(ANI0)

Data 1
(ANI0)

Data 2
(ANI1)

Data 5
(ANI0)

Data 6

(ANI1)

Data 11

(ANI0)

Data 11

(ANI0)

Data 12

(ANI1)

Data 18

(ANI5)

Data 21

(ANI6)

Data 2
(ANI1)

Data 3
(ANI2)

Data 3
(ANI2)

Data 4
(ANI3)

Data 7
(ANI0)

Data 8
(ANI1)

Data 8
(ANI1)

Data 9
(ANI2)

Data 9
(ANI2)

Data 10

(ANI3)

Data 10

(ANI3)

Data 13

(ANI4)

Data 13

(ANI4)

Data 17

(ANI4)

Data 19

(ANI4)

Data 20

(ANI5)

Data 20

(ANI5)

Data 14

(ANI5)

Data 14

(ANI5)

Data 15

(ANI6)

Data 15

(ANI6)

Data 16

(ANI7)

Data 16

(ANI7)

Data 4
(ANI3)

<4>

<4>

<8>

A hardware trigger is 
generated during A/D 
conversion operation.

<6>

ADS is rewritten 
during A/D 
conversion operation.

<7>

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

ADCS is cleared 
to 0 during A/D 
conversion
operation.

ADCE is cleared to 0. <10>

Data 5
(ANI0)

Data 17

(ANI4)

ANI0 to ANI3

ANI4 to ANI7

<9>

The trigger is not

acknowledged.

Data 19

(ANI4)