PXS20RM Datasheet, PDF (895/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

FlexRay Communication Controller
26.7.7.3.1 Transmit Data Not Available
If transmit data are not available, i.e. the transmit buffer is not committed FR_MBCCSRt[CMT]=0 and/or
locked FR_MBCCSRt[LCKS]=1,
a) for the cycles in the set {4n}, which is assigned to both buffers, the receive buffer will be found
and the node can receive data, and
b) for the cycles in the set {4n+2}, which is assigned to the receive buffer only, the receive buffer
will be found and the node can receive data.
The receive cycles are shown in Figure 26-163
RX
RX
RX
RX
RX
012345678
RX
RX
59 60 61 62 63
Figure 26-163. Transmit Data Not Available
26.7.7.3.2 Transmit Data Available
If transmit data are available, i.e. the transmit buffer is committed FR_MBCCSRt[CMT]=1 and not locked
FR_MBCCSRt[LCKS]=0,
a) for the cycles in the set {4n}, which is assigned to both buffers, the transmit buffer will be found
and the node transmits data.
b) for the cycles in the set {4n+2}, which is assigned to the receive buffer only, the receive buffer
will be found and the node can receive data.
The receive and transmit cycles are shown in Figure 26-163
TX
RX
TX
RX
TX
012345678
TX
RX
59 60 61 62 63
Figure 26-164. Transmit Data Not Available
Freescale Semiconductor
PXS20 Microcontroller Reference Manual, Rev. 1
26-183