mc9s12xf512 Freescale Semiconductor, Inc, mc9s12xf512 Datasheet - Page 459

• Manufacturer Part Number: mc9s12xf512
• Description: S12x Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

FlexRay protocol states are highlighted in
13.1.4
The FlexRay block is a FlexRay communication controller that implements the FlexRay Communications
System Protocol Specification, Version 2.1 Rev A.
The FlexRay block has three main components:
A block diagram of the FlexRay block with its surrounding modules is given in
The protocol engine has two transmitter units TxA and TxB and two receiver units RxA and RxB for
sending and receiving frames through the two FlexRay channels. The time control unit (TCU) is
responsible for maintaining global clock synchronization to the FlexRay network. The overall activity of
the PE is controlled by the sequencer engine (SEQ).
The controller host interface provides host access to the module’s configuration, control, and status
registers, as well as to the message buffer configuration, control, and status registers. The message buffers
themselves, which contain the frame header and payload data received or to be transmitted, and the slot
status information, are stored in the FlexRay Memory (FRM).
The clock domain crossing unit implements signal crossing from the CHI clock domain to the PE clock
domain and vice versa, to allow for asynchronous PE and CHI clock domains.
Freescale Semiconductor
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Controller host interface (CHI)
Protocol engine (PE)
Clock domain crossing unit (CDC)
Host CPU
System
Memory
Overview
MC9S12XF - Family Reference Manual, Rev.1.19
Figure 13-1. FLEXRAY Block Diagram
FLEXRAY
CHI
BMIF
SEARCH
green
BCU
LUT
HIF
italics. An example is the state
config
Chapter 13 FlexRay Communication Controller (FLEXRAY)
PE
SEQ
TCU
RxA
TxA
Figure
POC:normal
13-1.
RXD_A
TXD_A
TXE_A
RXD_B
TXD_B
TXE_B
STB0
STB1
STB2
STB3
active.
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