MPC5566 Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor
22-9
c
22.3.3
Register Descriptions
The FlexCAN2 registers are described in this section. There are four separate, identical FlexCAN2
modules: A, B, C, and D. In the following sections, the ‘
x
’ in the registers’ names represents the individual
module.
0110
OVERRUN: A frame was
overwritten into a full buffer.
0010
If the code indicates OVERRUN but the CPU reads the
C/S word and then unlocks the MB, when a new frame is
written to the MB the code returns to FULL.
0110
If the code already indicates OVERRUN, and yet another
new frame must be written, the MB is overwritten again,
and the code remains OVERRUN. See
for details about overrun behavior.
0XY1
1
BUSY: FlexCAN is updating the
contents of the MB. The CPU
must not access the MB.
0010
EMPTY buffer was written with a new frame (XY was 01).
0110
FULL/OVERRUN buffer was overwritten (XY was 11).
1
For TX message buffers (see
), the BUSY bit must be ignored when read.
Table 22-6. Message Buffer Code for TX Buffers
RTR
Initial TX
Code
Code after
Successful
Transmission
Description
X
1000
—
INACTIVE: MB does not participate in the arbitration process.
0
1100
1000
Transmit data frame unconditionally once. After transmission, the MB
automatically returns to the INACTIVE state.
1
1100
0100
Transmit remote frame unconditionally once. After transmission, the
MB automatically becomes and RX MB with the same ID.
0
1010
1010
Transmit a data frame whenever a remote request frame with the
same ID is received. This MB participates simultaneously in both the
matching and arbitration processes. The matching process
compares the ID of the incoming remote request frame with the ID of
the MB. If a match occurs this MB is allowed to participate in the
current arbitration process and the CODE field is automatically
updated to ‘1110’ to allow the MB to participate in future arbitration
runs. When the frame is eventually transmitted successfully, the
Code automatically returns to ‘1010’ to restart the process again.
0
1110
1010
The MBM generates this code as a result of match to a remote
request frame. The data frame is transmitted unconditionally once,
and then the code automatically returns to ‘1010’. The CPU can write
the code with the same effect.
Table 22-5. Message Buffer Codes for RX Buffers (continued)
RX Code before
RX Frame
Description
RX Code after
RX Frame
Comment
Summary of Contents for MPC5566
Page 81: ...Introduction MPC5566 Microcontroller Reference Manual Rev 2 1 24 Freescale Semiconductor...
Page 135: ...Signal Description MPC5566 Microcontroller Reference Manual Rev 2 2 54 Freescale Semiconductor...
Page 189: ...Reset MPC5566 Microcontroller Reference Manual Rev 2 4 20 Freescale Semiconductor...
Page 603: ...Flash Memory MPC5566 Microcontroller Reference Manual Rev 2 13 38 Freescale Semiconductor...
Page 609: ...SRAM MPC5566 Microcontroller Reference Manual Rev 2 14 6 Freescale Semiconductor...
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