SAB-C509-LM SIEMENS [Siemens Semiconductor Group], SAB-C509-LM Datasheet - Page 55

• Manufacturer Part Number: SAB-C509-LM
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

A/D Conversion Timing
An A/D conversion is internally started by writing into the SFR ADDATL with dummy data. A write
to SFR ADDATL will start a new conversion even if a conversion is currently in progress. Basically,
the A/D conversion procedure is divided into three parts :
The total A/D conversion time is defined by t
t
parameter as shown in figure 29.
Figure 29
A/D Conversion Timing
Semiconductor Group
CO
– Sample phase (t
– Conversion phase (t
– Write result phase (t
. The duration of the two phases of an A/D conversion is specified by its specific timing
ADCL1
Conversion Clock
0
0
1
1
Prescaler
ADCL0
0
1
0
1
S
), used for sampling the analog input voltage.
ADST1 ADST0
CO
WR
Sample Clock
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Prescaler
), used for the real A/D conversion.(includes calibration)
), used for writing the conversion result into the ADDAT registers.
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
8 x t
16 x t
32 x t
64 x t
16 x t
32 x t
64 x t
128 x t
32 x t
64 x t
128 x t
256 x t
64 x t
128 x t
256 x t
512 x t
ADCC
Sample
Time
IN
t
IN
IN
IN
IN
IN
IN
IN
IN
IN
S
54
IN
IN
IN
IN
IN
IN
which is the sum of the two phase times t
40 x t
80 x t
160 x t
320 x t
Conversion
Time
t
CO
IN
IN
IN
IN
48 x t
56 x t
72 x t
104 x t
96 x t
112 x t
144 x t
208 x t
192 x t
224 x t
288 x t
416 x t
384 x t
448 x t
576 x t
832 x t
t
ADCC
ConversionTime
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
CPU Cycles
Number of
138
12
17
16
18
24
34
32
37
48
69
64
74
96
8
9
C509-L
S
and