mfr4200 Freescale Semiconductor, Inc, mfr4200 Datasheet - Page 46

• Manufacturer Part Number: mfr4200
• Description: Flexray Communication Controllers
• Manufacturer: Freescale Semiconductor, Inc

Device Overview
2.4
2.4.1
The MFR4200 device operates only in one user mode — the normal mode. In normal mode, different host
interfaces can be selected, each with its own associated external pin and interface configurations. The
device has no low power modes.
2.4.2
As IF_SEL[0:1] and CLK_S[0:1] signals share pins with physical layer interface signals, pullup/down
devices must be used for selection. Recommended pullup/down resistor values for the IF_SEL[0:1] and
CLK_S[0:1] inputs are given in
2.4.3
The FlexRay communication controller can be connected to and controlled by microcontrollers with two
types of interface. The MCU type is selected by the IF_SEL0 and IF_SEL1 inputs as shown in
Section 2.1.3.1, “Interface
The CC latches the values of the IF_SEL0 and IF_SEL1 signals when it leaves the hard reset state. The
CC configures the interface for the type of MCU based on the latched values. The CC latches the values
again after it has left the hard reset state (see
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The listed values are calculated for the MFR4200 physical layer connection where no internal pullup/down resistors are
assumed in the Electrical PHY at the TXD_BG1, BGT, ARM and MT interface lines. If an Electrical PHY device has internal
pullup/down resistors connected to those signals, then the external pullup/down resistor values must be recalculated to
ensure that V
Refer to
IO, Regulator, and Analog Supply Level (V
Table 2-9. Recommended Pullup/down Resistor Values for IF_SEL[0:1] and CLK_S[0:1] Inputs
Modes of Operation
Section A.1.9, “I/O
Overview
Recommended Pullup/down Resistor Values
Host Controller Interfaces
IL
If the CC senses an unsupported mode on its IF_SEL pins, it stops all
internal operations, does not perform or respond to any host transactions,
stays in configuration mode, and does not integrate into the communication
process. The following steps must be taken to select a correct MCU interface
mode:
1. IF_SEL0, IF_SEL1 must be set to AMI or to HCS12 mode;
2. The hard reset signal of the CC must be asserted again.
requirements for pulldown resistors or V
3.3V
5V
Characteristics” for more information on VIL, VIH and VDD5.
Selection”.
Table
2-9.
MFR4200 Data Sheet, Rev. 0
DD5
)
Section 3.9.1, “Hard Reset
NOTE
Pullup Resistor
IH
requirements for pullup resistors for the chosen VDD5 are met.
16
10
1
Pulldown Resistor
State”).
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Freescale Semiconductor
kOhm
kOhm
Units