MC9S08DZ16 FREESCALE [Freescale Semiconductor, Inc], MC9S08DZ16 Datasheet - Page 174

• Manufacturer Part Number: MC9S08DZ16
• Description: 8-Bit HCS08 Central Processor Unit (CPU)
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Chapter 10 Analog-to-Digital Converter (S08ADC12V1)
10.1.3
The ADC module is capable of performing conversions using the MCU bus clock, the bus clock divided
by two, the local asynchronous clock (ADACK) within the module, or the alternate clock, ALTCLK. The
alternate clock for the MC9S08DZ60 Series MCU devices is the external reference clock (MCGERCLK).
The selected clock source must run at a frequency such that the ADC conversion clock (ADCK) runs at a
frequency within its specified range (f
determined by the ADIV bits.
ALTCLK is active while the MCU is in wait mode provided the conditions described above are met. This
allows ALTCLK to be used as the conversion clock source for the ADC while the MCU is in wait mode.
ALTCLK cannot be used as the ADC conversion clock source while the MCU is in either stop2 or stop3.
10.1.4
The ADC hardware trigger, ADHWT, is the output from the real time counter (RTC). The RTC counter
can be clocked by either MCGERCLK or a nominal 1 kHz clock source.
The period of the RTC is determined by the input clock frequency, the RTCPS bits, and the RTCMOD
register. When the ADC hardware trigger is enabled, a conversion is initiated upon an RTC counter
overflow.
The RTC can be configured to cause a hardware trigger in MCU run, wait, and stop3.
174
ADCH
00000
00001
00010
00011
00100
00101
00110
00111
01000
01001
01010
01011
01100
01101
01110
Alternate Clock
Hardware Trigger
Channel
AD10
AD11
AD12
AD13
AD14
AD0
AD1
AD2
AD3
AD4
AD5
AD6
AD7
AD8
AD9
PTA2/ADP2/ACMP1P-
PTA3/ADP3/ACMP1O
PTA1/ADP1/ACMP1+
PTA0/ADP0/MCLK
Table 10-1. ADC Channel Assignment
PTB2/ADP10
PTB3/ADP11
PTB4/ADP12
PTB5/ADP13
PTB6/ADP14
PTB0/ADP8
PTB1/ADP9
PTA4/ADP4
PTA5/ADP5
PTA6/ADP6
PTA7/ADP7
MC9S08DZ60 Series Data Sheet, Rev. 4
Input
ADCK
) after being divided down from the ALTCLK input as
11000–
ADCH
01111
10000
10001
10010
10011
10100
10101
10110
10111
11001
11010
11011
11100
11101
11110
AD24 through AD25
Reserved
Channel
V
V
AD15
AD16
AD17
AD18
AD19
AD20
AD21
AD22
AD23
AD26
AD27
REFH
Freescale Semiconductor
Temperature Sensor
Internal Bandgap
PTB7/ADP15
PTC0/ADP16
PTC1/ADP17
PTC2/ADP18
PTC3/ADP19
PTC4/ADP20
PTC5/ADP21
PTC6/ADP22
PTC7/ADP23
Reserved
Reserved
V
V
Input
REFH
2
1