MPC563XM Reference Manual, Rev. 1
Freescale Semiconductor
963
Preliminary—Subject to Change Without Notice
24.3.3
Debug Mode
Upon a debug mode entry request, EQADC behavior will vary according to the status of the DBG field in
Section 24.5.2.1, “EQADC Module Configuration Register (EQADC_MCR)
0b00, the debug mode entry request is ignored. If DBG is programmed to 0b10 or to 0b11, the EQADC
will enter debug mode. In case the EQADC SSI is enabled, the free running clock (FCK) output to external
device will not stop when DBG is programmed to 0b11, but FCK will stop in low phase, when DBG is
programmed to 0b10.
During debug mode, the EQADC will not transfer commands from any CFIFOs, no null messages will be
transmitted to the external device, no data will be returned to any RFIFO, no hardware trigger event will
be captured, and all EQADC registers can be accessed as in Normal mode. The latter implies that CFIFOs
can still be triggered using software triggers, since no scheme is implemented to write-protect registers
during debug mode. DMA and interrupt requests continue to be generated as in Normal Mode.
If at the time the debug mode entry request is detected, there are commands in the on-chip CBuffers that
were already under execution, these commands will be completed but the generated results, if any, will not
be sent to the RFIFOs until debug mode is exited. Commands whose execution has not started will not be
executed until debug mode is exited.The clock associated with an on-chip ADC stops, during its low phase,
after the ADC ceases executing commands. The time base counter will only stop after all on-chip ADCs
cease executing commands.
When exiting debug mode, the EQADC relies on the CFIFO operation modes and on the CFIFO status to
determine the next command entry to transfer.
The EQADC internal behavior after the debug mode entry request is detected differs depending on the
status of command transfers.
•
No command transfer is in progress.
The EQADC immediately halts future command transfers from any CFIFO.
If a null message is being transmitted, EQADC will complete the serial transmission before halting
future command transfers. If valid data (conversion result or data read from an ADC register) is
received at the end of transmission, it will not be sent to an RFIFO until debug mode is exited.
If the null message transmission is aborted, the EQADC will complete the abort procedure before
halting future command transfers from any CFIFO. The message of the CFIFO that caused the abort
of the previous serial transmission will only be transmitted after debug mode is exited.
•
Command transfer is in progress.
EQADC will complete the transfer and update CFIFO status before halting future command
transfers from any CFIFO. Command transfers to the internal CBuffers are considered completed
when a command is written to the buffers.
Command transfers to the external device are considered completed when the serial transmission of
the command is completed. If valid data (conversion result or data read from an ADC register) is
received at the end of a serial transmission, it will not be sent to an RFIFO until debug mode is
exited. The CFIFO status bits will still be updated after the completion of the serial transmission,
therefore, after debug mode entry request is detected, the EQADC status bits will only stop
changing several system clock cycles after the on-going serial transmission completes.