Freescale Semiconductor FlexRay MFR4310 - External Clock and Host Interface Selection; External 4;10;40 Mhz Output Clock; Table 2-5. CLKOUT Frequency Selection; Modes of Operation

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Device Overview

MFR4310 Reference Manual, Rev. 2

Freescale Semiconductor 45

2.4.4.3 VDD2_5, VSS2_5 — Core Power Pins

Power is supplied to the MFR4310 core through VDD2_5 and VSS2_5. This 2.5 V supply is derived from

the internal voltage regulator. No static load is allowed on these pins. If VDDR is tied to ground, the

internal voltage regulator is turned off.

NOTE

No load is allowed except for bypass capacitors.

2.4.4.4 VDDA, VSSA — Power Supply Pins for VREG

VDDA, VSSA are the power supply and ground input pins for the voltage regulator. They also provide the

reference voltages for the internal voltage regulator.

2.4.4.5 VDDOSC, VSSOSC — Power Supply Pins for OSC

VDDOSC, VSSOSC provide operating voltage and ground for the oscillator. This allows the supply

voltage to the oscillator to be bypassed independently. This 2.5 V voltage is generated by the internal

voltage regulator.

NOTE

No load is allowed except for bypass capacitors.

2.5 Modes of Operation

Refer to Section 3.1.6, “Modes of Operation” for full descriptions of the MFR4310 Disabled and Normal

modes of operation.

2.6 External Clock and Host Interface Selection

2.6.1 External 4/10/40 MHz Output Clock

A continuous external 4/10/40 MHz output clock signal is provided by the CC on the CLKOUT pin. See

Section 2.4.3.15, “CLKOUT — Clock Output” for details of when this signal is active.

The output frequency of the CLKOUT signal is selected by the CLK_S[1:0] input pins, in accordance with

Table 2-5:

Table 2-5. CLKOUT Frequency Selection

CLKOUT Function

CLK_S0 CLK_S1

0 0 4 MHz output

1 0 10 MHz output