A-D Converter
M30240 Group
Rev.1.00 Sep 24, 2003 Page 103 of 360
1.2.24.1 One-shot mode
In one-shot mode, the pin selected using the analog input pin select bit is used for one-shot A-D con-
version.Table 1.31 shows the specifications of one-shot mode. Figure 1.99 shows the A-D control reg-
ister in one-shot mode.
Figure 1.99: A-D conversion register in one-shot mode
Table 1.31: One-shot mode specification
Item Specification
Function The pin selected by the analog input pin select bit is used for one A-D conversion
Start condition Writing “1” to A-D conversion start flag
Stop condition
•End of A-D conversion (A-D conversion start flag changes to “0”, except when
external trigger is selected)
•Writing “0” to A-D conversion start flag
Interrupt request generation
timing
End of A-D conversion
Input pin One of AN
0
to AN
7
, as selected
Reading of result of A-D converter Read A-D register corresponding to selected pin
A-D control register 0 (Note 1)
Symbol Address When reset
ADCON0 03D616 00000XXX2
b7 b6 b5 b4 b3 b2 b1 b0
Analog input pin select
bit
Bit symbol Bit name Function
CH1
CH2
A-D operation mode
select bit 0
MD0
MD1
Trigger select bit 0 : Software trigger
1 : AD
TRG
trigger
TRG
ADST
A-D conversion start flag 0 : A-D conversion disabled
1 : A-D conversion started
Frequency select bit 0
0: f
AD
/4 is selected
1: f
AD
/2 is selected
CKS0
WR
00
A-D control register 1
(Note)
Symbol Address When reset
ADCON1 03D716 0016
Bit name FunctionBit symbol
b7 b6 b5 b4 b3 b2 b1 b0
A-D sweep pin
select bit
SCAN0
SCAN1
MD2
BITS
8/10-bit mode select bit
0 : 8-bit mode
1 : 10-bit mode
VCUT
Vref connect bit
A-D operation mode
select bit 1
0 : Any mode other than repeat sweep
mode 1
1 : Vref connected
WR
Invalid in one-shot mode
0
0 0 0 : AN
0
is selected
0 0 1 : AN
1
is selected
0 1 0 : AN
2
is selected
0 1 1 : AN
3
is selected
1 0 0 : AN
4
is selected
1 0 1 : AN
5
is selected
1 1 0 : AN
6
is selected
1 1 1 : AN
7
is selected (Note 2)
b2 b1 b0
0 0 : One-shot mode (Note 2)
b4 b3
CH0
1
Note 1: If the A-D control register is rewritten during A-D conversion, the conversion
result is indeterminate.
Note 2: When changing A-D operation mode, set analog input pin again.
Frequency select bit1
0 : f
AD
/2 or f
AD
/4 is selected
1 : f
AD
is selected
CKS1
Note: If the A-D control register is rewritten during A-D conversion, the conversion
result is indeterminate.
Reserved bit
Always set to "0"
0
0
To Next Page
Need help?
General
