MC9RS08KA8RM Datasheet, PDF (111/190 Pages) Freescale Semiconductor, Inc – MC9RS08KA8 Features

Analog-to-Digital Converter (RS08ADC10V1)
While in wait mode, the bus clock, bus clock divided by two, and ADACK are available as conversion
clock sources. Using ALTCLK as the conversion clock source in wait is dependent on the definition of
ALTCLK for this MCU. Consult the module introduction for information on ALTCLK specific to this
MCU.
A conversion complete event sets the COCO and generates an ADC interrupt to wake the MCU from wait
mode if the ADC interrupt is enabled (AIEN = 1).
10.4.7 MCU Stop Mode Operation
The STOP instruction puts the MCU in a low power-consumption standby mode during which most or all
clock sources on the MCU are disabled.
10.4.7.1 Stop Mode With ADACK Disabled
If the asynchronous clock, ADACK, is not the conversion clock, executing a STOP instruction aborts the
current conversion and places the ADC in its idle state. The contents of ADCRH and ADCRL are
unaffected by stop mode.After exiting from stop mode, a software or hardware trigger is required to
resume conversions.
10.4.7.2 Stop Mode With ADACK Enabled
If ADACK is the conversion clock, the ADC continues operation during stop mode. For guaranteed ADC
operation, the MCU’s voltage regulator must remain active during stop mode. Consult the module
introduction for configuration information for this MCU.
If a conversion is in progress when the MCU enters stop mode, it continues until completion. Conversions
can be initiated while the MCU is in stop mode by means of the hardware trigger or if continuous
conversions are enabled.
A conversion complete event sets the COCO and generates an ADC interrupt to wake the MCU from stop
mode if the ADC interrupt is enabled (AIEN = 1).
NOTE
The ADC module to wake the system from low power stop and cause the
MCU to begin consuming run-level currents without generating a system
level interrupt. To prevent this, your application must ensure that the data
transfer blocking mechanism (discussed in Section 10.4.4.2, “Completing
Conversions.”) is cleared when entering stop and continuing ADC
conversions.
10.5 Initialization Information
This section gives basic direction on how to initialize and configure the ADC module. Among other
options, you can configure the module for:
• 8-bit or 10-bit resolution
• single or continuous conversion
MC9RS08KA8 Series Reference Manual, Rev. 3
Freescale Semiconductor
111