mc9s08qg4 Freescale Semiconductor, Inc, mc9s08qg4 Datasheet - Page 126

• Manufacturer Part Number: mc9s08qg4
• Description: Hcs08 Microcontrollers Microcontroller Family
• Manufacturer: Freescale Semiconductor, Inc

Chapter 9 Analog-to-Digital Converter (S08ADC10V1)
126
ADLSMP
ADICLK
ADLPC
MODE
Field
ADIV
6:5
3:2
1:0
7
4
Reset:
W
R
Low Power Configuration — ADLPC controls the speed and power configuration of the successive
approximation converter. This is used to optimize power consumption when higher sample rates are not required.
0 High speed configuration
1 Low power configuration: {FC31}The power is reduced at the expense of maximum clock speed.
Clock Divide Select — ADIV select the divide ratio used by the ADC to generate the internal clock ADCK.
Table 9-6
Long Sample Time Configuration — ADLSMP selects between long and short sample time. This adjusts the
sample period to allow higher impedance inputs to be accurately sampled or to maximize conversion speed for
lower impedance inputs. Longer sample times can also be used to lower overall power consumption when
continuous conversions are enabled if high conversion rates are not required.
0 Short sample time
1 Long sample time
Conversion Mode Selection — MODE bits are used to select between 10- or 8-bit operation. See
Input Clock Select — ADICLK bits select the input clock source to generate the internal clock ADCK. See
Table
ADLPC
9-8.
7
0
shows the available clock configurations.
MODE
ADIV
00
01
10
11
00
01
10
11
0
6
Table 9-5. ADCCFG Register Field Descriptions
Figure 9-10. Configuration Register (ADCCFG)
MC9S08QG8 and MC9S08QG4 Data Sheet, Rev. 4
ADIV
8-bit conversion (N=8)
Reserved
10-bit conversion (N=10)
Reserved
Table 9-6. Clock Divide Select
Table 9-7. Conversion Modes
0
5
Divide Ratio
1
2
4
8
ADLSMP
0
4
Mode Description
Description
0
3
MODE
Input clock ÷ 2
Input clock ÷ 4
Input clock ÷ 8
Clock Rate
Input clock
0
2
Freescale Semiconductor
0
1
ADICLK
Table
0
0
9-7.