Chapter 10 Analog-to-Digital Converter (ADC12B_LBA_V1)
S12ZVHY/S12ZVHL Family Reference Manual Rev. 1.05
Freescale Semiconductor
409
10.5.3.3
ADC List Usage and Conversion/Conversion Sequence Flow
Description
It is the user’s responsibility to make sure that the different lists do not overlap or exceed the system RAM
area respectively the CSL does not exceed the NVM area if located in the NVM. The error flag IA_EIF
will be set for accesses done outside the system RAM area and will cause an error interrupt if enabled for
lists that are located in the system RAM.
Generic flow for ADC register load at conversion sequence start/restart:
•
It is mandatory that the ADC is idle (no ongoing conversion or conversion sequence).
•
It is mandatory to have at least one CSL with valid entries. See also
Section 10.8.7.2, “Restart CSL
execution with currently active CSL
Section 10.8.7.3, “Restart CSL execution with new/other
CSL (alternative CSL becomes active CSL) — CSL swapping
scenarios.
•
A Restart Event occurs, which causes the index registers to be cleared (register ADCCIDX and
ADCRIDX are cleared) and to point to the top of the corresponding lists (top of active RVL and
CSL).
•
Load conversion command to background conversion command register 1.
•
The control bit(s) RSTA (and LDOK if set) are cleared.
•
Wait for Trigger Event to start conversion.
Generic flow for ADC register load during conversion:
•
The index registers ADCCIDX is incremented.
•
The inactive background command register is loaded with a new conversion command.
Generic flow for ADC result storage at end of conversion:
•
Index register ADCRIDX is incremented and the conversion result is stored in system RAM. As
soon as the result is successfully stored, any conversion interrupt flags are set accordingly.
•
At the conversion boundary the other background command register becomes active and visible in
the ADC register map.
•
If the last executed conversion command was of type “End Of Sequence”, the ADC waits for the
Trigger Event.
•
If the last executed conversion command was of type “End Of List” and the ADC is configured in
“Restart Mode”, the ADC sets all related flags and stays idle awaiting a Restart Event to continue.
•
If the last executed conversion command was of type “End Of List” and the ADC is configured in
“Trigger Mode”, the ADC sets all related flags and automatically returns to top of current CSL and
is awaiting a Trigger Event to continue.
•
If the last executed conversion command was of type “Normal Conversion” the ADC continues
command execution in the order of the current CSL (continues conversion).
