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FlexRay Communication Controller (FlexRAY)
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
26-121
In this mode, the internal message transfer from the commit side to the transmit side is started for a double
transmit message buffer when all of the following conditions are fulfilled
1. the commit side is in the Idle state
2. the commit site message data are valid (MBCCSR(2
n
)[CMT] = 1)
3. the transmit side is in one of the states Idle, CCSa, or CCMa
4. the transmit side contains either no valid message data (MBCCSR(2
n
+ 1)[CMT] = 0) or
the message data were transmitted at least once (MBCCSR(2
n
+ 1)[DVAL] = 1)
An example of a streaming commit mode state change diagram is given in
. In this example,
both the commit and the transmit side do not contain valid message data and the application provides two
messages. The message buffer does not match the next slot.
Figure 26-134. Internal Message Transfer in Streaming Commit Mode
Immediate Commit Mode
The intention of the immediate commit mode is to transmit the
latest
data provided by the application. This
implies that it is not guaranteed that each provided message will be transmitted at least once.
The immediate commit mode is configured by setting the message buffer commit mode bit MCM in the
Message Buffer Configuration, Control, Status Registers (MBCCSRn)
.
In this mode, the internal message transfer from the commit side to the transmit side is started for one
double transmit message buffer when all of the following conditions are fulfilled
1. The commit side is in the Idle state.
2. The commit site message data are valid (MBCCSR(2
n
)[CMT] = 1).
3. The transmit side is in one of the states Idle, CCSa, or CCMa.
It is not checked whether the transmit side contains no valid message data or valid message data were
transmitted at least once. If message data are valid and not transmitted, they may be overwritten.
An example of a streaming commit mode state change diagram is given in
. In this example,
both the commit and the transmit side do not contain valid message data, and the application provides two
messages and the first message is gets overwritten. The message buffer does not match the next slot.
Idle
Commi
t
T
ransmit
Idle
HL
HLck
Side
Si
de
slot s
slot s+1
slot s+2
search[s+1]
slot s
tart
slot
st
art
slot
st
art
HU
CCITx
Idle
IS
CCITx
IE
Idle
HL
HLck
HU
Idle
Idle
no internal message transfer,
until message transmitted
Summary of Contents for PXN2020
Page 1: ...PXN20 Microcontroller Reference Manual Devices Supported PXN2020 PXN2120 PXN20RM Rev 1 06 2011...
Page 42: ...PXN20 Microcontroller Reference Manual Rev 1 lxiv Freescale Semiconductor...
Page 64: ...Introduction PXN20 Microcontroller Reference Manual Rev 1 1 22 Freescale Semiconductor...
Page 112: ...Signal Description PXN20 Microcontroller Reference Manual Rev 1 3 44 Freescale Semiconductor...
Page 118: ...Resets PXN20 Microcontroller Reference Manual Rev 1 4 6 Freescale Semiconductor...
Page 372: ...e200z6 Core Z6 PXN20 Microcontroller Reference Manual Rev 1 13 8 Freescale Semiconductor...
Page 412: ...e200z0 Core Z0 PXN20 Microcontroller Reference Manual Rev 1 14 14 Freescale Semiconductor...
Page 821: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 27 49...
Page 822: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 27 50 Freescale Semiconductor...
Page 1376: ...Memory Map PXN20 Microcontroller Reference Manual Rev 1 A 118 Freescale Semiconductor...