Setup - Panasonic F77G User Manual

Chapter 15 A/D Converter
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.
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 ) more than 800 ns and less than 15.26 s. Table 15-3-2 shows the machine clock (fosc, fx, fs)
AD
and the A/D converter clock (T
Table 15-3-2 A/D Conversion Clock and A/D Conversion Cycle
ANCK1
0
1
For the system clock (fs), refer to Chapter 2. 2-5 Clock Switching.
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
ANSH1 ANSH0
0
0
1
0
1
1
XV - 10
Operation
Table 15-3-1 Input Pins of A/D Converter Setup
ANCHS2
0
1
). (calculated as fs = fosc/2, fx/4)
AD
A/D
ANCK0 conversion
clock
0 fs/2
1 fs/4
0 fs/8
1 fx x 2
Sampling Time of A/D Conversion and A/D Conversion Time
Sampling time
(Ts) at T =800 ns
AD
T x 2 9.60 s
AD
T x 6 12.80 s
AD
T x 18 22.40 s
AD
Reserved -
ANCHS1 ANCHS0
0
0
1
0
1
1
0
0
1
0
1
1
A/D conversion cycle (TAD)
at oscillation for high speed
at fosc=20 MHz at fosc=8.38 MHz
200.00 ns 477.33 ns
(no usable) (no usable )
400.00 ns
954.65 ns
(no usable)
800.00 ns 1.91 s
15.26 s 15.26 s
A/D conversion time
at T =954.65 ns
AD
11.46 s
15.27 s
26.73 s
-
A/D pin
AN0 pin
AN1 pin
AN2 pin
AN3 pin
AN4 pin
AN5 pin
AN6 pin
Reserved
at oscillation for low speed
at fx=32.768 kHz
244.14 s
(no usable )
488.28 s
(no usable )
976.56 s
(no usable )
15.26 s
at T =1.91 s at T =15.26 s
AD AD
22.92 s 183.12 s
30.56 s 244.16 s
53.48 s 427.28 s
- -