mfr4200 Freescale Semiconductor, Inc, mfr4200 Datasheet - Page 178

• Manufacturer Part Number: mfr4200
• Description: Flexray Communication Controllers
• Manufacturer: Freescale Semiconductor, Inc

MFR4200 FlexRay Communication Controller
Dynamic segment
In the dynamic segment, if several valid frames are pending within the interface, the frame with the highest
priority (lowest frame ID) is selected next.
The CC transmission procedure is described in detail in the frame processing section of the PWD
document. The most important points are as follows.
The CC changes the following bits if the message buffer has been sent.
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1. IFLG
2. BUFCMT
3. VALID (depending on the TT bit of the BUFCSnR register — see
IFLG
BUFCMT
VALID (depending on the TT bit of the BUFCSnR register — see
Control, Configuration and Status
In the dynamic segment, different minislot sequences are possible on both channels (concurrent
sending of different IDx on both channels).
Pending frames are selected in accordance with their identifier and their filter configuration.
Frames overlapping with the network idle time (NIT), defined by the NITCR (see
Section 3.2.3.3.18, “Network Idle Time Configuration Register
transmitted.
If there are two or more transmit message buffers with the same identifier, the message buffer with
the lowest number wins the internal arbitration and will be transmitted; the remaining message
buffer(s) with matching filters will be removed from the arbitration process until the next
communication cycle.
If a message buffer was committed for transmission (BUFCMT= 1) it becomes valid (VALID = 1)
after the buffer unlock operation. The host cannot lock it until it is transmitted; this prevents
changing of a message buffer’s fields, while it is waiting to be transmitted.
Only valid frames (VALID bit = 1) can be transmitted by the CC.
Only identifiers that are higher than the highest static identifier are allowed for the dynamic
segment.
If there are valid frames with the same frame ID, the CC must check their filter fields. If two or
more of them match the conditions of the transmit slot, the message buffer with the lowest address
wins the internal arbitration.
The CC does not transmit null frames in the dynamic segment.
If two message buffers are assigned to the same dynamic slot but to different transmission channels,
the CC transmits them on the same minislot number and assigned channels during transmission of
that dynamic slot.
Control, Configuration and Status
MFR4200 Data Sheet, Rev. 0
Register)
Register)
(NITCR)”), will be not
Section 3.4.1, “Message Buffer
Section 3.4.1, “Message Buffer
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