MC9S08SH4CTG Freescale, MC9S08SH4CTG Datasheet - Page 122

• Manufacturer Part Number: MC9S08SH4CTG
• Manufacturer: Freescale

Specifications of MC9S08SH4CTG

• Cpu Family: HCS08
• Device Core Size: 8b
• Frequency (max): 40MHz
• Interface Type: I2C/SCI/SPI
• Total Internal Ram Size: 256Byte
• # I/os (max): 13
• Number Of Timers - General Purpose: 1
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 16
• Package Type: TSSOP
• Program Memory Type: Flash
• Program Memory Size: 4KB
• Lead Free Status / RoHS Status: Compliant

Chapter 9 Analog-to-Digital Converter (S08ADCV1)
9.1.2
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 MC9S08SH8 MCU devices is the external reference clock (ICSERCLK).
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.
9.1.3
The ADC hardware trigger, ADHWT, is the output from the real time counter (RTC). The RTC counter
can be clocked by either ICSERCLK, ICSIRCLK 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 RTIE does not have to be set for RTC to cause a hardware trigger.
The RTC can be configured to cause a hardware trigger in MCU run, wait, and stop3.
9.1.4
To use the on-chip temperature sensor, the user must perform the following:
Equation 9-1
Temp = 25°C, using the ADC1 at f
where:
For temperature calculations, use the V
122
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•
•
Configure ADC for long sample with a maximum of 1 MHz clock
Convert the bandgap voltage reference channel (AD27)
— By converting the digital value of the bandgap voltage reference channel using the value of
Convert the temperature sensor channel (AD26)
— By using the calculated value of V
— V
— V
— m is the hot or cold voltage versus temperature slope in V/°C.
V
Characteristics”.
Alternate Clock
Hardware Trigger
Temperature Sensor
BG
TEMP
TEMP25
provides an approximate transfer function of the on-chip temperature sensor for V
the user can determine V
is the voltage of the temperature sensor channel at the ambient temperature.
is the voltage of the temperature sensor channel at 25°C.
Temp
MC9S08SH8 MCU Series Data Sheet, Rev. 3
ADCK
C
ADCK
= 25 - ( (V
TEMP25
= 1.0MHz and configured for long sample.
DD
) after being divided down from the ALTCLK input as
. For value of bandgap voltage, see
DD
and m values in the data sheet.
TEMP
, convert the digital value of AD26 into a voltage,
-V
TEMP25
) / m)
Section A.6, “DC
Freescale Semiconductor
DD
Eqn. 9-1
= 5.0V,
V
TEMP