Freescale Semiconductor FlexRay MFR4310 - Table 3-104. Double Transmit Message Buffer Host Transitions

FlexRay Module (FLEXRAYV4)
MFR4310 Reference Manual, Rev. 2
172 Freescale Semiconductor
3.4.6.4.3 Message Buffer Transitions
Application Transitions
The application transitions that can be triggered by the application using the commands described in
Table 3-104. The application issues the commands by writing to the Message Buffer Configuration,
Control, Status Registers (MBCCSRn). Only one command can be issued with one write access. Each
command is executed immediately. If the command is ignored, it must be issued again.
The enable and disable commands can be issued on the transmit side only. Any enable or disable command
issued on the commit side is ignored without notification. The transitions triggered depend on the value of
the EDS bit. The enable and disable commands affect the commit side and the transmit side at the same
time. If the application triggers the disable transition HD while the transmit side is in one of the states
CCSa, CCSaCCITx, CCNf, CCNfCCITx, CCMa, CCMaCCITx, CCTx, or CCSu, the disable
transition has no effect (command is ignored) and the message buffer state is not changed. No notification
is given to the application.
The lock and unlock commands can be issued on the commit side only. Any lock or unlock command
issued on the transmit side are ignored and the double transmit buffer lock error flag DBL_EF in the CHI
Error Flag Register (CHIERFR) is set. The transitions triggered depend on the current value of the LCKS
bit. The lock and unlock commands only affect the commit side. If the application triggers the lock
transition HL while the commit side is in the state CCITx, the message buffer state is not changed and the
message buffer lock error flag LCK_EF in the CHI Error Flag Register (CHIERFR) is set.
Module Transitions
The module transitions that can be triggered by the FlexRay module are described in Table 3-105. The
transitions C1 and C2 apply to both sides of the message buffer and are applied at the same time. All other
FlexRay module transitions apply to the transmit side only.
CCSu 1 0 – SS Status Update. Message buffer status update. Update of status
flags, the slot status field, and the header index.
Note: The slot status field of the commit side is updated too, even if
the application has locked the commit side.
Table 3-104. Double Transmit Message Buffer Host Transitions
Transition Host Command Condition Description
HE
MBCCSR[2n+1].EDT:= 1
MBCCSR[2n+1].EDS = 0 Application triggers message buffer enable.
HD MBCCSR[2n+1].EDS = 1 Application triggers message buffer disable.
HL
MBCCSR[2n].LCKT:= 1
MBCCSR[2n].LCKS = 0 Application triggers message buffer lock.
HU MBCCSR[2n].LCKS = 1 Application triggers message buffer unlock.
Table 3-103. Double Transmit Message Buffer State Description (Transmit Side) (Continued)
State
MBCCSRn Access Region
Description
EDS LCKS Appl. Module