MPC563XM Reference Manual, Rev. 1
1102
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
Figure 24-93. CQueue/CFIFO Interface
24.7.2.2
RQueue/RFIFO Transfers
In transfers involving RQueues and RFIFOs, the DMAC moves data from a single source to a queue
destination as showed in
. The location of the data to be moved is indicated by the source
address, and the final destination for that data, by the destination address. For every DMA request issued
by the EQADC, the DMAC has to be configured to transfer a single result (16-bit data), pointed to by the
source address, from the RFIFO pop register to the RQueue, pointed to by the destination address. After
the service of a DMA request is completed, the destination address has to be updated to point to the
location where the next 16-bit result will be stored. The source address remains unchanged. When the last
expected result is written to the RQueue, one of the following actions is recommended. Refer to the DMAC
block guide for details about how this functionality is supported.
•
The corresponding DMA channel should be disabled.
•
The destination address should be updated pointed to the next location where new coming results
are stored, which can be the first entry of the current RQueue (cyclic queue), or the beginning of a
new RQueue.
Source Address
Command 1
Command 2
Command 3
.....
Command n-1
Command n
CFPRx
CQueue in
system memory
CFIFO
Push Register
One command transfer per DMA
request
Destination Address