Operation Of A/D Converter (In Single Sweep Mode) - Renesas M16C Series User Manual

M30245 Group

2.9.5 Operation of A/D Converter (in single sweep mode)

In single sweep mode, choose functions from those listed in Table 2.9.5. Operations of the circled items
are described below. Figure 2.9.10 shows timing chart, and Figure 2.9.11 shows the set-up procedure.
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Operation (1) Setting the A/D conversion start flag to "1" causes the A/D converter to start the conversion on
φA D
A / D c o n v e r s i o n
s t a r t f l a g
A D r e g i s t e r 0
A D r e g i s t e r 1
A D r e g i s t e r i
A / D c o n v e r s i o n
i n t e r r u p t r e q u e s t
b i t
Figure 2.9.10. Operation timing of single sweep mode
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
Table 2.9.5. Choosed functions
I t e m
Divided-by-4 f
O p e r a t i o n c l o c k
A D
by-3 f
O
/ f
R e s o l u t i o n O 8 - b i t / 1 0 - b i t
Analog input pin
A N
O t o A N
( 6 p i n s ) / A N
voltage input to the AN
(2) After the A/D conversion of voltage input to the AN
successive comparison register (conversion result) is transmitted to AD register 0. The A/D
converter converts all analog input pins selected by the user. The conversion result is trans-
mitted to AD register i corresponding to each pin, every time conversion on one pin is com-
pleted.
(3) When the A/D conversion on all the analog input pins selected is completed, the A/D conver-
sion interrupt request bit goes to "1". At this time, the A/D conversion start flag goes to "0".
The A/D converter stops operating.
( 1 ) S t a r t A / D c o n v e r s i o n
8 - b i t r e s o l u t i o n : 2 8 φA D
1 0 - b i t r e s o l u t i o n : 3 3 φA D
S e t t o " 1 " b y s o f t w a r e
" 1 "
" 0 "
" 1 "
" 0 "
N o t e : W h e n φA D f r e q u e n c y i s l e s s t h a n 1 M H
C o n v e r s i o n r a t e p e r a n a l o g i n p u t p i n i s 4 9
page 224 of 354
Set-up
/ divided-
AD
T r i g g e r f o r s t a r t i n g
/ divided-by-2 f
AD AD
A / D c o n v e r s i o n
AD
S a m p l e & H o l d
a n d A N ( 2 p i n s ) / A N
0 1 0
( 4 p i n s ) / A N t o A N
3 0 5
t o A N ( 8 p i n s )
0 7
pin.
0
( 2 )
After A/D conversion on AN
A/D converter begins converting all pins selected
8 - b i t r e s o l u t i o n : 2 8 φA D c y c l e s
c y c l e s
1 0 - b i t r e s o l u t i o n : 3 3 φA D
c y c l e s
R e s u l t
Cleared to "0" when interrupt request is accepted, or cleared by software
, s a m p l e a n d h o l d f u n c t i o n c a n n o t b e s e l e c t e d .
Z
φA D c y c l e s f o r 8 - b i t r e s o l u t i o n a n d 5 9
Item
O S o f t w a r e t r i g g e r
T r i g g e r b y A D
N o t a c t i v a t e d
O A c t i v a t e d
pin is completed, the content of the
0
pin is complete,
0
c y c l e s
Result
φA D c y c l e s f o r 1 0 - b i t r e s o l u t i o n .
2. A/D Converter
S e t - u p
T R G
( 3 )
A / D c o n v e r s i o n
i s c o m p l e t e
R e s u l t