
Introduction
MFR4200 Data Sheet, Rev. 0
22
Freescale Semiconductor
1.3
Terminology
Table 1-1. Acronyms and Abbreviations
Term
Meaning
AMI
Asynchronous memory interface
BG
Bus guardian
CC
Communication controller (an alternative term for the MFR4200)
ceil
Function ceil(x) returns the nearest integer greater than or equal to x
Cycle length in μT
The actual length of a cycle in μT for the ideal controller (± 0 ppm)
EBI
External bus interface
FSS
Frame start sequence
Host
The FlexRay CC host MCU
LSB
Less/least significant bit
MCU
Microcontroller
MSB
More/most significant bit
MT
Macrotick
μT
Microtick
NIT
Network idle time
PHY
Physical interface
PS
FlexRay Communications System Protocol Specification
PWD
Protocol working document
RX
Reception
TCU
Time control unit
TX
Transmission
TDMA
Time division multiplex access
Table 1-2. Notational Conventions
active-high
Names of signals that are active-high are shown in upper case text, without a ‘#’ symbol at the end.
Active-high signals are asserted (active) when they are high and negated when they are low.
active-low
A ‘#’ symbol at the end of a signal name indicates that the signal is active-low.
An active-low signal is asserted (active) when it is at the logic low level and is negated when it is at the
logic high level.
asserted
A signal that is asserted is in its active logic state. An active-low signal changes from high to low when
asserted; an active-high signal changes from low to high when asserted.
negated
A signal that is negated is in its inactive logic state. An active-low signal changes from low tohigh when
negated; an active-high signal changes fromhigh to low when negated.
set
To set a bit means to establish logic level one on the bit.
clear
To clear a bit means to establish logic level zero on the bit.