Freescale Semiconductor FlexRay MFR4310 - Page 131

FlexRay Module (FLEXRAYV4)
MFR4310 Reference Manual, Rev. 2
Freescale Semiconductor 131
9
LCKT
Lock/Unlock Trigger — This trigger bit is used to lock and unlock a message buffer. The message buffer lock is
triggered when the application writes 1 to this bit and the message buffer is not locked, i.e. the LCKS status bit
is 0. The message buffer unlock is triggered when the application writes 1 to this bit and the message buffer is
locked, i.e. the LCKS status bit is 1.
0 No effect
1 Trigger message buffer lock/unlock
Note: If the application writes 1 to this bit and 0 to the EDT bit, the write access to all other bits is ignored.
8
MBIE
Message Buffer Interrupt Enable — This control bit defines whether the message buffer generate an interrupt
request when its MBIF flag is set.
0 Interrupt request generation disabled
1 Interrupt request generation enabled
Message Buffer Status
4
DUP
Data Updated — This status bit applies only to receive message buffers. It is always 0 for transmit message
buffers. This bit provides information whether the frame header in the message buffer header field and the
message buffer data field were updated. See Section 3.4.6.3.4, “Message Buffer Status Update” for a detailed
description of the update condtions.
0 Frame Header and Message buffer data field not updated.
1 Frame Header and Message buffer data field updated.
3
DVAL
Data Valid — The semantic of this status bit depends on the message buffer type and transfer direction.
• Receive Message Buffer: Indicates whether the message buffer data field contains valid frame data. See
Section 3.4.6.3.4, “Message Buffer Status Update” for a detailed update description of the update conditions.
0 message buffer data field contains no valid frame data
1 message buffer data field contains valid frame data
• Single Transmit Message Buffer: Indicates whether the message is transferred again due to the state
transmission mode of the message buffer.
0 Message transferred for the first time.
1 Message is transferred again.
• Double Transmit Message Buffer: For the commit side it is always 0. For the transmit side it indicates whether
the message is transferred again due to the state transmission mode of the message buffer.
0 Message transferred for the first time.
1 Message is transferred again.
2
EDS
Enable/Disable Status — This status bit indicates whether the message buffer is enabled or disabled.
0 Message buffer is disabled.
1 Message buffer is enabled.
1
LCKS
Lock Status — This status bit indicates the current lock status of the message buffer.
0 Message buffer is not locked by the application.
1 Message buffer is locked by the application.
0
MBIF
Message Buffer Interrupt Flag — The semantic of this flag depends on the message buffer transfer direction.
• Receive Message Buffer: This flag is set when the slot status in the message buffer header field was updated
and this slot was not an empty dynamic slot. See Section 3.4.6.3.4, “Message Buffer Status Update” for a
detailed description of the update conditions.
0 slot status not updated
1 slot status updated and slot was not an empty dynamic slot
• Transmit Message Buffer: This flag is set when the slot status in the message buffer header field was updated.
Additionally this flag is set immediately when a transmit message buffer was enabled.
0 slot status not updated
1 slot status updated / message buffer recently enabled
Writing a 1 clears this flag. Writing a 0 does not change the flag state.
Table 3-75. MBCCSRn Field Descriptions (Continued)
Field Description