RapidIO Message Unit
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
16-51
16.3 RapidIO Message Unit
The RapidIO message unit handles multicast and non-multicast single-segment messages and
non-multicast multiple-segment messages. The RapidIO controller has two inbound and two
outbound message controllers.
The message passing programming model for inter-processor and inter-device communication
enables a producer to send a message across the interconnect fabric to the message hardware of a
consumer, called a mailbox. The receiving mailbox hardware places the message into a queue
located in local memory. A message consists of one to sixteen segments. When a configured
number of messages is received, an interrupt is generated (if enabled) to the interrupt controller
for the processor to process the messages. Messages can be queued for transmission in the
producer memory, and the message hardware processes them sequentially. Messages can also be
queued in consumer memory while software processes them sequentially. Software can configure
the depths of the queues in the producer and consumer memories. A multicast function allows
single-segment messages to be sent to multiple consumers.
The message unit is compliant with the message passing logical specification in the RapidIO
Interconnect Specification, Revision 1.2. The message passing model is most commonly used in
systems in which a processing element is allowed to access only memory that is local to itself,
processing elements communicate with each other through message passing, and communication
is address independent.
Each inbound message controller has a dedicated interrupt to notify software that a configured
number of messages have been received. Similarly, each outbound message controller has a
dedicated interrupt to notify software that there are no more messages for the outbound mailbox
controller. The message controller is managed through a set of run-time registers.
16.3.1
Features
The message unit supports two outbound message controllers with the following features:
Chaining and direct modes.
Multicast up to 32 RapidIO destinations for single-segment messages.
Transmission to any mailbox for a single-segment message.
Transmission to any mailbox for a multi-segment message.
Segment size up to 256 bytes.
Up to 16 segment messages with a total payload of up to 4 KB.
One entire message with up to a 16 message segments can be transmitted before a
response is received.
One entire single-segment message to all multicast destinations (up to 32) can be
transmitted before a response is received.
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 ...