MPC563XM Reference Manual, Rev. 1
1018
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
determine the RFIFO to which the ADC result should be sent. Once in an RFIFO, the ADC result is moved
to the corresponding RQueue by the host CPU or by the DMAC as they respond to interrupt and DMA
requests generated by the EQADC. The EQADC generates these requests whenever an RFIFO has at least
one entry.
NOTE:
While conversion results are returned, the EQADC is checking the number of
entries in the RFIFO and generating requests to empty it. The process of pushing
and popping ADC results to and from an RFIFO can occur simultaneously.
Figure 24-47. Result Flow during EQADC operation
24.6.2.2
Assumptions/Requirements Regarding the External Device
The external device exchanges command and result data with the EQADC through the EQADC SSI
interface. This section explains the minimum requirements an external device has to meet to properly
interface with the EQADC. Some assumptions about the architecture of the external device are also
described.
NOTE: x=0, 1, 2, 3, 4, 5
Inside EQADC
Host CPU
or
DMAC
ADC
y=0, 1, 2, 3, ...
System Memory
EQADC SSI
External Device
De
code
r
RQueue y
RFIFOx
16 bits
16 bits
ADC
Result Message
RFIFO Header
ADC Result
Logic
&
Buffers
EQADC SSI
DMA or interrupt requests
DMA Transaction
Done Signals
FIFO Control
Unit
Result
Format and
Calibration
On-Chip
Companion
EQADC PSI
Module
Resolution
Ad
ju
st