
MFR4200 FlexRay Communication Controller
MFR4200 Data Sheet, Rev. 0
172
Freescale Semiconductor
3.5.5
Buffer Reconfiguration in the Normal State of Operation
Reconfiguration procedure during the normal state of operation:
The host must follow the configuration principles and procedure as well as reconfiguration principles,
while reconfigures the message buffers during normal operation.
Reconfiguration principles:
1. Only single transmit message buffers for dynamic segment (STBDS) are reconfigurable in normal
operation.
2. States and parameters that are reconfigurable:
— Parameters of STBDS accessible for host write operations (see
Section , “Receive, receive
FIFO, and transmit message buffers are accessible to the host MCU only through the active
receive, active transmit, and active receive FIFO buffers.
” and
Section 3.4.1, “Message Buffer
Control, Configuration and Status Register
”).
3. Buffers, states and parameters that are not reconfigurable:
— FIFO size
— Double transmit message buffers
— Receive message buffers
— Buffers from transmit message buffers to receive message buffers, and vice versa
— All the filtering parameters (channel filters configuration, frame ID filters configuration
(except single transmit message buffers for dynamic segment), message ID filters configuration
and masks, message buffer filtering configuration)
— Buffers cannot be reassigned from static to dynamic segment, or vice versa.
— FIFO
— Buffers cannot be reconfigured from single to double transmit message buffers, or vice versa.
— Buffers assigned to the static segment are not reconfigurable
Figure 3-135
shows how CC buffers can be configured and reconfigured during the configuration state, and
reconfigured during the normal state of the CC: