M16C80 Datasheet, PDF (184/358 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/80 SERIES

M16C/80 Group
21. A/D Converter
(4) Repeat sweep mode 0
In repeat sweep mode 0, the pins selected using the A/D sweep pin select bit are used for repeat sweep
A/D conversion. Table 21.5 shows the specifications of repeat sweep mode 0. Figure 21.7 shows the A/
D control register in repeat sweep mode 0.
Table 21.5 Repeat sweep mode 0 specifications
Item
Specification
Function
The pins selected by the A/D sweep pin select bit are used for repeat sweep
A/D conversion
Start condition
Writing “1” to A/D conversion start flag
Stop condition
Writing “0” to A/D conversion start flag
Interrupt request generation timing None generated
Input pin
AN0 and AN1 (2 pins), AN0 to AN3 (4 pins), AN0 to AN5 (6 pins), or AN0 to AN7
(8 pins)
Reading of result of A/D converter Read A/D register corresponding to selected pin (at any time)
A/D control register 0 (Note)
b7 b6 b5 b4 b3 b2 b1 b0
11
Symbol
ADCON0
Address
039616
Bit symbol
Bit name
CH0
Analog input pin
select bit
CH1
When reset
00000XXX2
Function
Invalid in repeat sweep mode 0
RW
CH2
MD0
MD1
A/D operation mode
select bit 0
b4 b3
1 1 : Repeat sweep mode 0
TRG
ADST
Trigger select bit
A/D conversion start flag
0 : Software trigger
1 : ADTRG trigger
0 : A/D conversion disabled
1 : A/D conversion started
CKS0
Frequency select bit 0
0 : fAD/4 is selected
1 : fAD/2 is selected
Note: If the A/D control register is rewritten during A/D conversion, the conversion result is indeterminate.
A/D control register 1 (Note 1)
b7 b6 b5 b4 b3 b2 b1 b0
1
0
Symbol
ADCON1
Address
039716
When reset
0016
Bit symbol
Bit name
SCAN0
A/D sweep pin select bit
SCAN1
MD2
A/D operation mode
select bit 1
Function
When single sweep and repeat sweep mode 0
are selected
b1 b0
0 0 : AN0, AN1 (2 pins)
0 1 : AN0 to AN3 (4 pins)
1 0 : AN0 to AN5 (6 pins)
1 1 : AN0 to AN7 (8 pins)
0 : Any mode other than repeat sweep mode 1
RW
BITS
8/10-bit mode select bit 0 : 8-bit mode
1 : 10-bit mode
CKS1
Frequency select bit 1
(Note 3)
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 (Note 2)
b7 b6
0 0 : ANEX0 and ANEX1 are not used(Note 4)
0 1 : ANEX0 input is A/D converted(Note 5)
1 0 : ANEX1 input is A/D converted(Note 6)
1 1 : External op-amp connection mode(Note 7)
Note 1: If the A/D control register is rewritten during A/D conversion, the conversion result is indeterminate.
Note 2: Neither ‘01’ nor ‘10’ can be selected with the external op-amp connection mode bit.
Note 3: When f(XIN) is over 10 MHz, the fAD frequency must be under 10 MHz by dividing.
Note 4: Set "0" to PSL3_5 and PSL3_6 of the function select register B3.
Note 5: Set "1" to PSL3_5 of the function select register B3.
Note 6: Set "1" to PSL3_6 of the function select register B3.
Note 7: Set "1" to PSL3_5 and PSL3_6 of the function select register B3.
Figure 21.7 A/D conversion register in repeat sweep mode 0
Rev.1.00 Aug. 02, 2005 ^{Page 173} of 329
REJ09B0187-0100