3-1 setup – Panasonic MN101C77C User Manual
Page 484
Chapter 15 A/D Converter
Operation
XV - 10
Sampling Time (Ts) of A/D Converter Setup
The sampling time of A/D converter is set by the ANSH1 to 0 flag of the ANCTR0 register. The sampling
time of A/D converter depends on external circuit, so set the right value by analog input impedance.
Table 15-3-3 Sampling Time of A/D Conversion and A/D Conversion Time
Clock of A/D Converter Setup
The A/D converter clock is set by the ANCK1 to 0 flag of the ANCTR0 register. Set the A/D converter
clock (T
AD
) more than 800 ns and less than 15.26
µ
s. Table 15-3-2 shows the machine clock (fosc, fx, fs)
and the A/D converter clock (T
AD
). (calculated as fs = fosc/2, fx/4)
Table 15-3-2 A/D Conversion Clock and A/D Conversion Cycle
Table 15-3-1 Input Pins of A/D Converter Setup
15-3-1
Setup
Input Pins of A/D Converter Setup
Input pins for A/D converter is selected by the ANCH2 to 0 flag of the ANCTR1 register.
For the system clock (fs), refer to Chapter 2. 2-5 Clock Switching.
ANCHS2
ANCHS1
ANCHS0
A/D pin
0
AN0 pin
1
AN1 pin
0
AN2 pin
1
AN3 pin
0
AN4 pin
1
AN5 pin
0
AN6 pin
1
Reserved
0
1
0
1
0
1
at oscillation for low s peed
at fos c=20 MHz
at fos c=8.38 MHz
at fx=32.768 kHz
200.00 ns
477.33 ns
244.14
µ
s
(no usable)
(no usable )
(no usable )
400.00 ns
488.28
µ
s
(no usable)
(no usable )
976.56
µ
s
(no usable )
1
fx x 2
15.26
µ
s
15.26
µ
s
15.26
µ
s
ANCK1
ANCK0
A/D
conversion
clock
at oscillation for high speed
A/D convers ion cycle (TAD)
1
0
0
1
0
1.91
µ
s
954.65 ns
fs/2
fs/4
fs/8
800.00 ns
Sampling time
(Ts)
at T
AD
=800 ns
at T
AD
=954.65 ns
at T
AD
=1.91
µ
s
at T
AD
=15.26
µ
s
0
T
AD
x 2
9.60
µ
s
11.46
µ
s
22.92
µ
s
183.12
µ
s
1
T
AD
x 6
12.80
µ
s
15.27
µ
s
30.56
µ
s
244.16
µ
s
0
T
AD
x 18
22.40
µ
s
26.73
µ
s
53.48
µ
s
427.28
µ
s
1
Reserved
-
-
-
-
A/D convers ion time
0
1
ANSH1
ANSH0