FlexRay Module Registers
1401
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
FlexRay Module
26.3.2.8 Input Buffer
Double buffer structure consisting of input buffer host and input buffer shadow. While the host can write to
input buffer host, the transfer to the message RAM is done from input buffer shadow. The input buffer
holds the header and data sections to be transferred to the selected message buffer in the message RAM.
It is used to configure the message buffers in the message RAM and to update the data sections of
transmit buffers.
When updating the header section of a message buffer in the Message RAM from the Input Buffer, the
Message Buffer Status as described in Message Buffer Status (MBS), Message Buffer Status (MBS) is
automatically reset to 0.
The header sections of message buffers belonging to the receive FIFO can only be (re)configured when
the communication controller is in DEFAULT_CONFIG or CONFIG state. For those message buffers only
the payload length configured and the data pointer need to be configured by bits PLC of the Write Header
Section 2 (WRHS2) and by bits DP of Write Header Section 3 (WRHS3). All information required for
acceptance filtering is taken from the FIFO rejection filter and the FIFO rejection filter mask.
26.3.2.8.1 Write Data Section Registers (WRDS[1-64])
Holds the data words to be transferred to the data section of the addressed message buffer. The data
words (DW
n
) are written to the message RAM in transmission order from DW
1
(byte0, byte1) to DW
PL
(DW
PL
= number of data words as defined by the payload length configured in PLC of the Write Header
Section 2 (WRHS2).
and
illustrate this register.
Figure 26-180. Write Data Section Registers (WRDSn) [offset_CC = 400h-4FCh]
31
16
MD
R/W-0
15
0
MD
R/W-0
LEGEND: R/W = Read/Write; -
n
= value after reset
Table 26-152. Write Data Section Registers (WRDSn) Field Descriptions
Bit
Field
Description
31-0
MD
Message data.
Note: DW127 is located on WRDS64.MD. In this case WRDS64.MD is unused (no valid data).The input
buffer RAMs are initialized to 0 when leaving hardware reset or by the controller host interface
command CLEAR_RAMS.
MD(31-24) = DW
2n
, byte
4n-1
MD(23-16) = DW
2n
, byte
4n-2
MD(15-8) = DW
2n-1
, byte
4n-3
MD(7-0) = DW
2n-1
, byte
4n-4