M16C80 Datasheet, PDF (185/358 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/80 SERIES

M16C/80 Group
21. A/D Converter
(5) Repeat sweep mode 1
In repeat sweep mode 1, all pins are used for A/D conversion with emphasis on the pin or pins selected
using the A/D sweep pin select bit. Table 21.6 shows the specifications of repeat sweep mode 1. Figure
21.8 shows the A/D control register in repeat sweep mode 1.
Table 21.6 Repeat sweep mode 1 specifications
Item
Specification
Function
All pins perform repeat sweep A/D conversion, with emphasis on the pin or
pins selected by the A/D sweep pin select bit
Example : AN0 selected AN0 AN1 AN0 AN2 AN0 AN3, etc
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 to AN7
With emphasis on the pin AN0 (1 pin), AN0 and AN1 (2 pins), AN0 to AN2 (3 pins), AN0 to AN3 (4 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
When reset
00000XXX2
Bit symbol
CH0
CH1
Bit name
Analog input pin
select bit
Function
Invalid in repeat sweep mode 1
RW
CH2
MD0
MD1
A/D operation mode
select bit 0
b4 b3
1 1 : Repeat sweep mode 1
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
1
Symbol
ADCON1
Address
039716
When reset
0016
Bit symbol
Bit name
Function
RW
SCAN0
SCAN1
MD2
A/D sweep pin select bit
A/D operation mode
select bit 1
When repeat sweep mode 1 is selected
b1 b0
0 0 : AN0 (1 pin)
0 1 : AN0, AN1 (2 pins)
1 0 : AN0 to AN2 (3 pins)
1 1 : AN0 to AN3 (4 pins)
1 : Repeat sweep mode 1
BITS
CKS1
8/10-bit mode select bit
Frequency select bit 1
(Note 3)
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 (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 21.8 A/D conversion register in repeat sweep mode 1
Rev.1.00 Aug. 02, 2005 ^{Page 174} of 329
REJ09B0187-0100