MFR4200 datasheet(39/260 Pages) FREESCALE

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Signal Descriptions

MFR4200 Data Sheet, Rev. 0

Freescale Semiconductor

MT is active, irrespective of which physical layer is selected. If the RS485 driver type is selected, this pin

is not used.

This signal should be connected to the Bus Guardians on each channel. The pin can be configured to

provide either high or reduced output drive.

CLK_S1 is the CLKOUT clock frequency selection input signal. See Table 2-2.

NOTE

CLK_S[0:1] signals are inputs during the internal reset sequence and are

latched by the internal reset signal level.

While the CLK_S1 value is being latched, the output drive control is

disabled and the internal pulldown resistor is connected to the pin.

As CLK_S[0:1] signals share pins with Physical Layer Interface signals,

pullup/down devices must be used for the selection. Recommended

pullup/down resistor values for the CLK_S[0:1] inputs are given in

Section 2.4.2, “Recommended Pullup/down Resistor Values”.

2.2.3.11

ARM/DBG1/CLK_S0 — Bus Guardian ARM, Debug Strobe Point 1, Clock

Output Select 0

ARM is an output signal from the CC to a bus guardian. If a bus guardian device is not used in an

application, this pin may be left open.

ARM is active, irrespective of which physical layer is selected. If the RS485 driver type is selected, this

pin is not used.

This signal should be connected to the bus guardian on each channel. The pin can be configured to provide

either high or reduced output drive.

DBG1 is the debug strobe point output 1. The function output on this pin is selected by the debug port

control register. Refer to Section 3.10, “Debug Port” for more information.

CLK_S0 is the CLKOUT clock frequency selection input signal. See Table 2-2.

NOTE

CLK_S[0:1] signals are inputs during the internal reset sequence and are

latched by the internal reset signal level.

While the CLK_S0 value is being latched, the output drive control is

disabled and the internal pulldown resistor is connected to the pin.

As 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 CLK_S[0:1] inputs are given in the

Section 2.4.2, “Recommended Pullup/down Resistor Values”.

MFR4200 Datasheet(PDF) 39 Page - Freescale Semiconductor, Inc