Chapter 10 Analog-to-Digital Converter (ADC12B_LBA_V1)
S12ZVHY/S12ZVHL Family Reference Manual Rev. 1.05
356
Freescale Semiconductor
10.2.1
Modes of Operation
10.2.1.1
Conversion Modes
This architecture provides
single
,
multiple,
or
continuous
conversion
on a
single channel
or on
multiple
channels based on the Command Sequence List
.
10.2.1.2
MCU Operating Modes
•
MCU Stop Mode
Before issuing an MCU Stop Mode request the ADC should be idle (no conversion or conversion
sequence or Command Sequence List ongoing).
If a conversion, conversion sequence, or CSL is in progress when an MCU Stop Mode request is
issued, a Sequence Abort Event occurs automatically and any ongoing conversion finish. After the
Sequence Abort Event finishes, if the STR_SEQA bit is set (STR_SEQA=1), then the conversion
result is stored and the corresponding flags are set. If the STR_SEQA bit is cleared
(STR_SEQA=0), then the conversion result is not stored and the corresponding flags are not set.
The microcontroller then enters MCU Stop Mode without SEQAD_IF being set.
Alternatively, the Sequence Abort Event can be issued by software before an MCU Stop Mode
request. As soon as flag SEQAD_IF is set the MCU Stop Mode request can be is issued.
With the occurrence of the MCU Stop Mode Request until exit from Stop Mode all flow control
signals (RSTA, SEQA, LDOK, TRIG) are cleared.
After exiting MCU Stop Mode, the following happens in the order given with expected event(s)
depending on the conversion flow control mode:
— In ADC conversion flow control mode “Trigger Mode” a Restart Event is expected to
simultaneously set bits TRIG and RSTA, causing the ADC to execute the Restart Event
(CMD_IDX and RVL_IDX cleared) followed by the Trigger Event. The Restart Event can be
generated automatically after exit from MCU Stop Mode if bit AUT_RSTA is set.
— In ADC conversion flow control mode “Restart Mode”, a Restart Event is expected to set bit
RSTA only (ADC already aborted at MCU Stop Mode entry hence bit SEQA must not be set
simultaneously) causing the ADC to execute the Restart Event (CDM_IDX and RVL_IDX
cleared). The Restart Event can be generated automatically after exit from MCU Stop Mode if
bit AUT_RSTA is set.
— The RVL buffer select (RVL_SEL) is not changed if a CSL is in process at MCU Stop Mode
request. Hence the same buffer will be used after exit from Stop Mode that was used when the
Stop Mode request occurred.