RapidIO Programming Model
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
16-171
16.6.62
Outbound Message x Descriptor Queue Dequeue Pointer Address
Registers (OMxDQDPAR)
OMxDQDPAR contain the address of the first descriptor in memory to be processed. Software
must initialize this register to point to the first descriptor in memory. After the descriptor is
processed, the message unit controller increments the outbound message descriptor queue
dequeue pointer address in OMxDQDPAR to point to the next descriptor. If the outbound
message descriptor queue enqueue pointer and the outbound message descriptor queue dequeue
pointer are not equal (indicating that the queue is not empty), the message unit controller reads
the next descriptor from memory for processing. If the enqueue and dequeue pointers are equal
after the message unit controller increments the dequeue pointer, the queue is empty and the
message unit halts until the processor increments the enqueue pointer. Incrementing the pointer
indicates that a new descriptor was added to the queue and is ready for processing. If the queue
becomes empty and OMxMR[QEIE] is set, OMxSR[QEI] is set and an interrupt is generated.
When software initializes these registers, they must be aligned on a boundary equal to the number
of queue entries
×
32 bytes (the size of each queue descriptor).For example, if there are eight
entries in the queue, the register must be 256-byte aligned. The number of queue entries is set in
OMnMR[CIRQ_SIZ].
OM[0–1]DQDPAR
Outbound Message 0–1 Descriptor
Offset 0 x*0x100
Queue Dequeue Pointer Address Registers
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
DQDPA
TYPE
R/W
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
DQDPA
—
TYPE
R/W
R
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table 16-105. OMxDQDPAR Field Descriptions
Bits
Reset Description
DQDPA
31–5
0
Descriptor Dequeue Pointer Address
Contains the address of the first descriptor in memory to process. The descriptor must be aligned
to a 32-byte boundary. For proper operation, this field should be modified only when the
outbound message controller is not enabled.
—
4–0
0
Reserved. Write to zero for future compatibility.
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...