25 A/D CONVERTER (ADC10)
25-10
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
1 (R/W): Left justify mode (10-bit conversion results
→
ADD[15:6], ADD[5:0] = 0)
0 (R/W): Right justify mode (10-bit conversion results
→
ADD[9:0], ADD[15:10] = 0) (default)
D6
ADMS: Conversion Mode Select Bit
Selects an A/D conversion mode.
1 (R/W): Continuous conversion mode
0 (R/W): One-time conversion mode (default)
Writing 1 to ADMS sets the A/D converter to continuous conversion mode. In this mode, A/D conver-
sions in the range of the channels selected by ADCS[2:0] and ADCE[2:0] are executed continuously
until stopped with software.
When ADMS is 0, the A/D converter operates in one-time conversion mode. In this mode, A/D conver-
sion is terminated after all inputs in the range of the channels selected by ADCS[2:0] and ADCE[2:0]
have been converted once.
D[5:4]
ADTS[1:0]: Conversion Trigger Select Bits
Selects a trigger source to start A/D conversion.
6.3 Trigger Selection
Table 25.
ADTS[1:0]
Trigger source
0x3
External trigger (#ADTRIG)
0x2
Reserved
0x1
T8 Ch.2
0x0
Software trigger
(Default: 0x0)
When an external trigger is used, the #ADTRIG pin must be configured in advance using the port func-
tion select bit (see the “I/O Ports (GPIO)” chapter). A/D conversion is started when the #ADTRIG
signal goes Low. When T8 Ch.2 is used, since its underflow signal serves as a trigger, set the underflow
cycle and other conditions for the timer.
D3
Reserved
D[2:0]
ADST[2:0]: Sampling Time Setting Bits
Sets the analog input sampling time.
6.4 Sampling Time Settings
Table 25.
ADST[2:0]
Sampling time
(in conversion clock cycles)
0x7
9 cycles
0x6
8 cycles
0x5
7 cycles
0x4
6 cycles
0x3
5 cycles
0x2
4 cycles
0x1
3 cycles
0x0
2 cycles
(Default: 0x7)
Note: Do not alter ADST[2:0] from the default value (0x7).