Datasheet

Chapter 9 Analog-to-Digital Converter (S08ADC10V1)
MC9S08SG32 Data Sheet, Rev. 8
Freescale Semiconductor 135
9.3.8 Pin Control 1 Register (APCTL1)
The pin control registers disable the digital interface to the associated MCU pins used as analog inputs to
reduce digital noise and improve conversion accuracy. APCTL1 controls the pins associated with channels
0–7 of the ADC module.
Some MCUs may not use all bits implemented in this register. Bits in this register that do not have
associated external analog inputs have no control function. Consult the ADC channel assignment in the
module introduction.
Table 9-9. Input Clock Select
ADICLK Selected Clock Source
00 Bus clock
01 Bus clock divided by 2
10 Alternate clock (ALTCLK)
11 Asynchronous clock (ADACK)
7654 3 210
R
ADPC7 ADPC6 ADPC5 ADPC4 ADPC3 ADPC2 ADPC1 ADPC0
W
Reset: 0 0 0 0 0 0 0 0
Figure 9-10. Pin Control 1 Register (APCTL1)
Table 9-10. APCTL1 Register Field Descriptions
Field Description
7
ADPC7
ADC Pin Control 7 — ADPC7 controls the pin associated with channel AD7.
0 AD7 pin I/O control enabled
1 AD7 pin I/O control disabled
6
ADPC6
ADC Pin Control 6 — ADPC6 controls the pin associated with channel AD6.
0 AD6 pin I/O control enabled
1 AD6 pin I/O control disabled
5
ADPC5
ADC Pin Control 5 — ADPC5 controls the pin associated with channel AD5.
0 AD5 pin I/O control enabled
1 AD5 pin I/O control disabled
4
ADPC4
ADC Pin Control 4 — ADPC4 controls the pin associated with channel AD4.
0 AD4 pin I/O control enabled
1 AD4 pin I/O control disabled
3
ADPC3
ADC Pin Control 3 — ADPC3 controls the pin associated with channel AD3.
0 AD3 pin I/O control enabled
1 AD3 pin I/O control disabled
2
ADPC2
ADC Pin Control 2 — ADPC2 controls the pin associated with channel AD2.
0 AD2 pin I/O control enabled
1 AD2 pin I/O control disabled