APPLICATIONS
7905 Group User’s Manual Rev.1.0
18-4
18.1 Application example of A-D converter
b7
b0
00
0
b7
b0
0
0
b7
b0
0
00
0
00
0
b7
b0
0
000
b7
b0
1
1
b7
b0
0
00
0
100
1
b7
b0
0 00 0
b7
b0
1
b7
b0
0
00
0
10 10
b7
b0
0 000
b7
b0
1
Continued from preceding Figure 18.1.1.
Setting of pin AN9 to one-shot mode (Note)
Setting of pin AN8 to one-shot mode
Setting of pin AN10 to one-shot mode (Note)
A-D control register 0
(Address 1E16)
One-shot mode
A-D conversion start bit
0 : A-D conversion halts.
A-D conversion frequency (
φAD) select bit 0
See Table 12.2.1.
A-D control register 1
(Address 1F16)
Resolution select bit
1 : 10-bit resolution mode
A-D conversion frequency (
φAD) select bit 1
See Table 12.2.1.
VREF connection select bit
0 : Pin VREF is connected.
A-D control register 2
(Address DB16)
Analog input pin select bits 1
b1 b0
b2
b3
1 0 0 0: Pin AN8 is selected.
b1 b0
b2
b3
1 0 0 1: Pin AN9 is selected.
b1 b0
b2
b3
1 0 1 0: Pin AN10 is selected.
: It may be either “0” or “1.”
Interrupt disabled, no interrupt requested
A-D conversion interrupt control register
(Address 7016)
Interrupt disabled
No interrupt requested
Setting of A-D conversion start bit to “1.”
A-D control register 0
(Address 1E16)
A-D conversion starts.
Trigger generated, A-D conversion started
0: During A-D
conversion.
1: A-D conversion, using one-shot
mode with pin AN8, is completed.
1: A-D conversion, using one-shot
mode with pin AN9, is completed.
1: A-D conversion, using one-shot
mode with pin AN10, is completed.
A-D conversion
interrupt request
bit = “1” ?
A-D control register 2
(Address DB16)
Analog input pin select bits 1
Interrupt disabled, no interrupt requested
A-D conversion interrupt control register
(Address 7016)
Interrupt disabled
No interrupt requested
Setting of A-D conversion start bit to “1.”
A-D control register 0
(Address 1E16)
A-D conversion starts.
Trigger generated, A-D conversion started
A-D conversion
interrupt request
bit = “1” ?
0: During A-D
conversion.
A-D control register 2
(Address DB16)
Analog input pin select bits 1
Interrupt disabled, no interrupt requested
A-D conversion interrupt control register
(Address 7016)
Interrupt disabled
No interrupt requested
Setting of A-D conversion start bit to “1.”
A-D control register 0
(Address 1E16)
A-D conversion starts.
Trigger generated, A-D conversion started
0: During A-D
conversion.
A-D conversion
interrupt request
bit = “1” ?
Continued on Figure 18.1.3.
Fig. 18.1.2 Application example of A-D converter, using single sweep mode with pins AN0 to AN11 (2)