MPC563XM Reference Manual, Rev. 1
1032
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
BUSY1[0:1] — BUSY Status field
BUSY0[0:1] — BUSY Status field
Refer to
Section , “Result Message Format for External Device Operation
24.6.3
Command/Result Queues
The Command and Result queues (CQueues and RQueues) are actually part of the EQADC system
although they are not hardware implemented inside the EQADC. Each CQueue entry is a 32-bit Command
Message.The last entry of a CQueue has the EOQ bit asserted to indicate that it is the last entry of the
CQueue. RQueue entry is a 16-bit data.
Section 24.6.2.1, “Overview and Basic Terminology
for a description of the message formats and their
flow in EQADC.
Refer to
Section 24.7.5, “CQueue and RQueues Usage
for examples of how CQueues and RQueues can
be used.
24.6.4
EQADC Command FIFOs
24.6.4.1
CFIFO Basic Functionality
There are six prioritized CFIFOs located in the EQADC. Each CFIFO is four entries deep, except CFIFO0
that can be configured to eight entries deep in extended mode, and each CFIFO entry is 32 bits long. A
CFIFO serves as a temporary storage location for the command messages stored on the CQueues in the
system memory. When a CFIFO is not full, the EQADC sets the corresponding CFFF bit in
Section 24.5.2.9, “EQADC FIFO and Interrupt Status Registers (EQADC_FISR)
. If CFFE is asserted in
Section 24.5.2.8, “EQADC Interrupt and DMA Control Registers (EQADC_IDCR)
generates requests for more commands from a CQueue. An interrupt request, served by the host CPU, is
generated when CFFS is negated, and a DMA request, served by the DMAC, is generated when CFFS is
asserted. The host CPU or the DMAC respond to these requests by writing to the
“EQADC CFIFO Push Registers (EQADC_CFPR)
NOTE:
The DMAC should be configured to write a single command (32-bit data) to the
CFIFO push registers for every asserted DMA request it acknowledges. Refer to
Section 24.7.2, “EQADC/DMAC Interface
for DMAC configuration guidelines.
NOTE:
CFIFO0 can be configured to work in an alternative way called Streaming Mode.
This mode is very different from the mode described here because it maintains some
stored commands to execute them several times in sequence and in loop.
NOTE:
Only whole words must be written to EQADC_CFPR. Writing half-words or bytes
to EQADC_CFPR will still push the whole 32-bit CF_PUSH field into the
corresponding CFIFO, but undefined data will fill the areas of CF_PUSH that were
not specifically designated as target locations for writing.