Module Operation
1254
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
FlexRay Module
Example of a 8/16/32-bit host access sequence:
•
Configure / update n-th message buffer through IBF
•
Wait until IBCR.IBSYH is reset
•
Write data section to WRDSn
•
Write header section to WRHS1,2,3
•
Write command mask: write IBCM.STXRH, IBCM.LHSH, IBCM.LDSH
•
Demand data transfer to target message buffer: write IBCR.IBRH(6-0)
Configure / update further message buffer through IBF in the same way.
NOTE:
Any write access to IBF while IBCR.IBSYH is 1 will set error flag EIR.IIBA in the Error
Interrupt Register to 1. In this case the write access has no effect.
Table 26-12. Assignment of Input Buffer Command Mask Bits
Position
Access
Bit
Function
18
r
STXRS
Set Transmission Request shadow ongoing or finished
17
r
LDSS
Load Data Section shadow ongoing or finished
16
r
LHSS
Load Header Section shadow ongoing or finished
2
r/w
STXRH
Set Transmission Request Host
1
r/w
LDSH
Load Data Section Host
0
r/w
LHSH
Load Header Section Host
Table 26-13. Assignment of Input Buffer Command Request Bits
Position
Access
Bit
Function
31
r
IBSYS
IBF Busy Shadow, signals ongoing transfer from IBF shadow to message RAM
22-16
r
IBRS(6-0)
IBF Request Shadow, number of message buffer currently / last updated
15
r
IBSYH
IBF Busy Host, transfer request pending for message buffer referenced by IBRH(6-0)
6-0
r/w
IBRH(6-0)
IBF Request Host, number of message buffer to be updated next
26.2.12.2.2 Data Transfer from Message RAM to Output Buffer
To read out a message buffer from the message RAM, the host has to write to the output buffer command
mask and command request register to trigger the data transfer. After a transfer has completed the host
can read the transferred data from the RDDSn, RDHS1,2,3, and MBS.