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Device Overview
MFR4200 Data Sheet, Rev. 0
26
Freescale Semiconductor
2.1.2
Implementation Details and Constraints
The MFR4200 provides two hardware selectable host interfaces:
— HCS12 interface, for direct connection to Freescale’s HCS12 family of microcontrollers.
The HCS12 interface clock signal used to synchronize data transfer can run at a maximum rate
of 8 MHz.
— Asynchronous memory interface (AMI), for asynchronous connection to microcontrollers.
Internal 40 MHz quartz oscillator.
Internal voltage regulator for the digital logic and the oscillator.
Hardware selectable clock output to drive external host devices: Disabled/4/10/40 MHz.
Maskable interrupt sources available over one interrupt output line.
Glueless electrical physical layer interface compatible with dedicated FlexRay physical layer.
Industry standard RS485 physical layer device can be used with additional glue logic.
Two pins have multiplexed strobe functions.
NOTE
Refer to
Chapter 3, “MFR4200 FlexRay Communication Controller
” for
more implementation details and constraints.
2.1.3
Modes of Operation
NOTE
This section depicts only the MFR4200 device modes, not the FlexRay
protocol operating modes of the MFR4200 FlexRay module. Refer to
Chapter 3, “MFR4200 FlexRay Communication Controller
for more
information on the FlexRay module operating modes.
Only one user mode is available on the MFR4200 — normal operating mode.
In normal operating mode, the selections described below are possible.
2.1.3.1
Interface Selection
The external interface is selected by means of the IF_SEL[0:1] pins, as shown in
Table 2-1
.
Table 2-1. Interface Selection
Pin
Interface
IF_SEL0
IF_SEL1
0
0
Reserved
0
1
HCS12 synchronous interface
1
0
Asynchronous Memory Interface
1
1
Reserved