M16C26 Datasheet, PDF (163/239 Pages) Renesas Technology Corp – 16-BIT CMOS SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES

Udenvdeelropment
Preliminary Specifications Rev.
Specifications in this manual are
A-D Converter
0.9
tentative
and
subject to change.
SINGLE-CHIP 16-BIT
M16C/26 Group
CMOS MICROCOMPUTER
(1) One-shot mode
In one-shot mode, the pin selected using the analog input pin select bits , is used for one-shot A-D
conversion. Table 1.16.3 shows the specifications of one-shot mode. Figure 1.16.4 shows the settings of
the A-D control registers in one-shot mode.
Table 1.16.3. One-shot mode specifications
Item
Function
Start condition
Stop condition
Interrupt request
generation timing
Input pin
Reading of A-D result
Specification
The pin selected by the analog input pin select bits is used for one A-D conversion
Writing "1" to the A-D conversion start flag
• End of A-D conversion (A-D conversion start flag changes to "0" - except when
external trigger is selected
• Writing "0" to the A-D conversion start flag
End of A-D conversion
Select one from AN0 to AN7
Read A-D register that corresponds to selected analog input pin
A-D control register 0 (Note 1)
b7 b6 b5 b4 b3 b2 b1 b0
00
Symbol
ADCON0
Address When reset
03D616 00000XXX2
Bit symbol
Bit name
Function
CH0
CH1
CH2
MD0
MD1
TRG
ADST
CKS0
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
0 : Software trigger
1 : ADTRG trigger
A-D conversion start flag 0 : A-D conversion disabled
1 : A-D conversion started
Frequency select bit 0 Refer to table 1.16.2
RW
(Note 2)
(Note 2)
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 pins again.
A-D control register 1 (Note 1)
b7 b6 b5 b4 b3 b2 b1 b0
1
0
Symbol
ADCON1
Address
03D716
When reset
0016
Bit symbol
Bit name
SCAN0
SCAN1
A-D sweep pin
select bit
Function
Invalid in one-shot mode
MD2
BITS
A-D operation mode
select bit 1
8/10-bit mode select bit
Set to 0 when this mode is selected
0 : 8-bit mode
1 : 10-bit mode
CKS1 _{Frequency select bit1 Refer to table 1.16.2}
RW
VCUT Vref connect bit (Note 2) 1 : Vref connected
Nothing is assigned.
In an attempt to write to these bits, write 0. The value, if read, turns out to be 0.
Note 1: If the A-D control register is rewritten during A-D conversion, the conversion result is indeterminate.
Note 2: If the VCUT bit is reset from "0" (Vref unconnected) to "1" (Vref connected), wait for 1 µs or more before starting
A-D conversion.
Figure 1.16.4. A-D conversion control registers in one-shot mode
Renesas Technology Corp.
157