NXP Semiconductors MC9S08LG16, Reference Manual

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Chapter 9 Analog-to-Digital Converter (S08ADC12V1)
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor 211
10.3.8 Pin Control 1 Register (APCTL1)
The pin control registers disable the I/O port control of MCU pins used as analog inputs. APCTL1 is used
to control the pins associated with channels 0–7 of the ADC module.
3:2
MODE
Conversion Mode Selection. MODE bits are used to select between 12-, 10-, or 8-bit operation. See Table 10-8 .
1:0
ADICLK
Input Clock Select. ADICLK bits select the input clock source to generate the internal clock ADCK. See
Table 10-9 .
Table 10-7. Clock Divide Select
ADIV Divide Ratio Clock Rate
00 1 Input clock
01 2 Input clock
÷
2
10 4 Input clock
÷
4
11 8 Input clock
÷
8
Table 10-8. Conversion Modes
MODE Mode Description
00 8-bit conversion (N=8)
01 12-bit conversion (N=12)
10 10-bit conversion (N=10)
11 Reserved
Table 10-9. Input Clock Select
ADICLK Selected Clock Source
00 Bus clock
01 Bus clock divided by 2
10 Alternate clock (ALTCLK)
11 Asynchronous clock (ADACK)
7 6 5 4 3 2 1 0
R
ADPC7 ADPC6 ADPC5 ADPC4 ADPC3 ADPC2 ADPC1 ADPC0
W
Reset: 0 0 0 0 0 0 0 0
Figure 10-10. Pin Control 1 Register (APCTL1)
Table 10-6. ADCCFG Register Field Descriptions (continued)
Field Description