M16C80 Datasheet, PDF (181/358 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/80 SERIES

M16C/80 Group
21. A/D Converter
(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 conver-
sion. Table 21.2 shows the specifications of one-shot mode. Figure 21.4 shows the A/D control register in
one-shot mode.
Table 21.2 One-shot mode specifications
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 AN0 to AN7, as selected
Reading of result of A/D converter Read A/D register corresponding to selected pin
A/D control register 0 (Note 1)
b7 b6 b5 b4 b3 b2 b1 b0
00
Symbol
ADCON0
Address
039616
When reset
00000XXX2
Bit symbol
Bit name
Function
RW
CH0
CH1
CH2
MD0
MD1
TRG
ADST
Analog input pin select
bit
b2 b1 b0
0 0 0 : AN0 is selected
0 0 1 : AN1 is selected
0 1 0 : AN2 is selected
0 1 1 : AN3 is selected
1 0 0 : AN4 is selected
1 0 1 : AN5 is selected
1 1 0 : AN6 is selected
1 1 1 : AN7 is selected
A/D operation mode
select bit 0
b4 b3
0 0 : One-shot mode
Trigger select bit
A/D conversion start flag
0 : Software trigger
1 : ADTRG trigger
0 : A/D conversion disabled
1 : A/D conversion started
(Note 2)
(Note 2)
CKS0
Frequency select bit 0
0: fAD/4 is selected
1: fAD/2 is selected
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.
A/D control register 1 (Note)
b7 b6 b5 b4 b3 b2 b1 b0
1
0
Symbol
ADCON1
Address
039716
When reset
0016
Bit symbol
Bit name
SCAN0
SCAN1
A/D sweep pin select
bit
Function
Invalid in one-shot mode
RW
MD2
BITS
CKS1
A/D operation mode
select bit 1
8/10-bit mode select
bit
Frequency select bit 1
(Note 2)
0 : Any mode other than repeat sweep
mode 1
0 : 8-bit mode
1 : 10-bit mode
0 : fAD/2 or fAD/4 is selected
1 : fAD is selected
VCUT Vref connect bit
1 : Vref connected
OPA0
OPA1
External op-amp
connection mode bit
b7 b6
0 0 : ANEX0 and ANEX1 are not used(Note 3)
0 1 : ANEX0 input is A/D converted(Note 4)
1 0 : ANEX1 input is A/D converted(Note 5)
1 1 : External op-amp connection mode(Note 6)
Note 1: If the A/D control register is rewritten during A/D conversion, the conversion result is indeterminate.
Note 2: When f(XIN) is over 10 MHz, the fAD frequency must be under 10 MHz by dividing.
Note 3: Set "0" to PSL3_5 and PSL3_6 of the function select register B3.
Note 4: Set "1" to PSL3_5 of the function select register B3.
Note 5: Set "1" to PSL3_6 of the function select register B3.
Note 6: Set "1" to PSL3_5 and PSL3_6 of the function select register B3.
Figure 21.4 A/D conversion register in one-shot mode
Rev.1.00 Aug. 02, 2005 ^{Page 170} of 329
REJ09B0187-0100