RapidIO Programming Model
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
16-185
16.6.74
Inbound Message x Frame Queue Enqueue Pointer Address
Registers (IMxFQEPAR)
IMxFQEPAR contains the address for the next message frame in memory to be added to the
queue. Software must initialize this register to match the frame queue dequeue pointer address.
When the mailbox controller receives a message, it writes the message data to the next location in
the queue (indicated by the address in IMxFQEPAR) and then increments IMxFQEPAR to point
to the next frame location in memory. This can result in a number of actions:
If the enqueue and dequeue pointers match, the queue is full and the mailbox controller
does not accept any more incoming messages, returning RETRY responses to the sending
devices until the queue is no longer full. If the IMxMR[QFIE] bit is set, the IMxMR[QFI]
bit is set and an interrupt is generated.
If the enqueue and dequeue pointers are the same before the register is incrememted, the
queue has changed from empty to not empty. If IMxMR[MIQIE] is set, IMxSR[MIQI] 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 x frame size. For example, if there are eight entries in the queue and the frame
size is 128 bytes, the register must be 1024-byte aligned. The number of queues is set in
IMxMR[CIRQ_SIZ] and the frame size is set in IMxMR[FRM_SIZ].
IM[0–1]FQEPAR
Inbound Message x Frame
Offset 0 x*0x100
Queue Enqueue Pointer Address Registers
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
FQEPA
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
FQEPA
—
TYPE
R/W
R
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table 16-117. IMxFQEPAR Field Descriptions
Bits
Reset Description
FQEPA
31–3
0
Frame Queue Enqueue Pointer Address
Contains the address of the next message frame to be added to the queue.
For proper operation, this field should be modified only when the inbound message controller
is not enabled.
—
2–0
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 ...