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Texas Instruments TMS320TCI648x User Manual

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SRIO Functional Description

Table 18. RX Buffer Descriptor Field Descriptions (continued)

Field

Description

ownership

Ownership: Indicates ownership of the message and is valid only on sop. This bit is set
by the DSP core and cleared by the port when the message has been transmitted. The
DSP core uses this bit to reclaim buffers.

0: The message is owned by the DSP core

1: The message is owned by the port

eoq

End Of Queue: Set by the port to indicate that the RX queue empty condition exists.
This bit is valid only on eop. The port determines the end of queue condition by a zero
next_descriptor_pointer.

0: The RX queue has more buffers available for reception.

1: The Descriptor buffer is the last buffer in the last message in the queue.

teardown_complete

Teardown Complete: Set by the port to indicate that the host commanded teardown
process is complete, and the channel buffers may be reclaimed by the host.

0: The port has not completed the teardown process.

1: The port has completed the commanded teardown process.

message_length

Message Length: Initially written by the DSP core to specify the maximum number of
double-words the buffer can receive. Updated by the peripheral (after receiving a
message) to indicate the actual number of double-words in the entire message.
Message payloads are limited to a maximum size of 512 double-words (4096 bytes).

000000000b: 512 double words

000000001b: 1 double word

000000010b: 2 double words

. . .

111111111b: 511 double words

src_id

Source Node ID: Unique node identifier of the source of the message. Written by the
DSP core.

tt

RapidIO tt field specifying 8- or 16-bit DeviceIDs. Written by the DSP core.

00b: 8-bit deviceIDs

01b: 16-bit deviceIDs

10: reserved

11: reserved

pri

Message Priority: Specifies the SRIO priority at which the message was sent. Written
by the DSP core.

cc

Completion Code: Written by the port.

000: Good completion. Message received.

001: Error, RX message length greater than supported buffer descriptor
message_length

010: Error, TimeOut on receiving one of the segments

011: DMA transfer error on one or more segments

100: Queue teardown completed, data invalid

101: 111 Reserved

mailbox

Destination Mailbox: Specifies the mailbox to which the message was sent. Written by
the DSP core.

000000b: Mailbox 0

000001b: Mailbox 1

. . .

000100b: Mailbox 4

. . .

111111b: Mailbox 63
For multi-segment messages, only the two LSBs of this mailbox are valid. Hardware
ignores the four MSBs if the incoming message has multiple segments.

Serial RapidIO (SRIO)

48

SPRUE13A – September 2006

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