PXD10RM Datasheet, PDF (128/1332 Pages) Freescale Semiconductor, Inc – PXD10 Microcontroller

Sample B Convert B Sample C Convert C Sample D Convert D Sample E Convert E
Sample C Abort C
Injected conversion of channels I and J
Sample I Convert I
Sample J Convert J Sample C Convert C
The ongoing channel conversion is interrupted and the injected
conversion chain is processed first, after the injected chain is
converted the normal chain conversion resumes from the channel at
which normal conversion was aborted.
Normal conversion resumes from
the last aborted channel.
Figure 5-3. Injected sample/conversion sequence
The injected conversion can be started by software setting the JSTART bit in the MCR; the current
conversion is suspended and the injected chain is converted. At the end of the chain, the JSTART bit in the
MSR is reset and the normal chain conversion is resumed.
The JSTART status bit in the MSR is automatically set when the Injected conversion starts. At the same
time the JSTART bit in the MCR is reset, allowing the software to program a new start of conversion. In
that case the new requested conversion starts after the running injected conversion is completed.
At the end of each injected conversion, an End Of Injected Conversion (JEOC) interrupt is issued (if
enabled by the corresponding mask bit) and at the end of the sequence an End Of Injected Chain (JECH)
interrupt is issued (if enabled by the corresponding mask bit).
If the content of all the injected conversion mask registers is zero (that is, no channel is selected) the
interrupt JECH is immediately issued after the start of conversion.
Once started, injected chain conversion cannot be interrupted by any other conversion type (it can,
however, be aborted; see Section 5.3.1.5, Abort conversion).
5.3.1.5 Abort conversion
Two different abort functions are provided.
• The user can abort the ongoing conversion by setting the ABORT bit in the MCR. The current
conversion is aborted and the conversion of the next channel of the chain is immediately started
(generating a new start pulse to the Analog ADC). In the case of an abort operation, the
NSTART/JSTART bit remains set and the ABORT bit is reset after the conversion of the next
channel starts. The EOC corresponding to the aborted channel is not generated. This behavior is
true for normal or triggered/Injected conversion modes. If the last channel of a chain is aborted, the
end of chain is reported generating an ECH interrupt.
• It is also possible to abort the current chain conversion by setting the ABORTCHAIN bit in the
MCR. In that case the behavior of the ADC depends on the MODE bit. In fact, if scan mode is
disabled, the NSTART bit is automatically reset together with the ABORTCHAIN bit. Otherwise,
if the MODE bit is set to ‘1’, a new chain conversion is started. The EOC of the current aborted
conversion is not generated but an ECH interrupt is generated to signal the end of the chain.
PXD10 Microcontroller Reference Manual, Rev. 1
5-6
Freescale Semiconductor
Preliminary—Subject to Change Without Notice