N.A.T. NAT-MCH, Техническое справочное руководство

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NAT-MCH BASE-Module– Technical Reference Manual
Version 2.10 © N.A.T. GmbH 14
3.4.2 USB Debug Port
The front panel micro USB connector available on the NAT-MCH BASE-Module is
connected to the USB interface of the ColdFire MCF54452. It provides a console
interface for configuration and monitoring. The USB interface is running in USB
Device Mode. Hardware version 3.4 or higher supports also USB Host Mode (not
for LC version!).
A special USB-to-RS232 adapter cable can be ordered from N.A.T. GmbH.
Connecting this cable to the
NAT-MCH USB port (configured to Host Mode) has
the advantage that a terminal connection will not get lost after a “reboot” or
power-cycle.
3.4.3 Clock Interface
The NAT-MCH BASE-Module can be equipped with various External Reference
Clock Transceiver Modules. The available transceiver modules differ in the number
of supported clock signals, in the supported electrical standard (e.g. LVDS, TTL,
CMOS) and the supported connector.
The external clock interfaces are routed from the transceiver module to the
CLK-
Module . Therefore the external clock interfaces can only be used in collaboration
with the NAT-MCH CLK-Module .
At the moment the following External Clock Transceiver Modules are available:
3.4.3.1 Coax-IO
The Coax-IO transceiver module supports two SMA connectors at the face plate.
Each connector is connected to its independent amplifier circuit. Each amplifier
circuit can be configured as receiver or transmitter.
Configured as transmitter the output signal coming from the Clock Module FPGA is
transmitted via a simple CMOS driver. This driver is connected to the SMA
connector via AC-coupling.
The amplifier circuit first comes really into operation if configured as receiver. The
receiver part is designed to be able to work with a wide range of input voltages,
as well as signal forms (e.g. sine wave, rectangle).
To be independent of any DC-offset the receiver part is also connected via AC-
coupling.
The main part of the amplifier is a comparator that transfers the input signal from
the SMA connector into a rectangle signal with a peak to peak voltage of 3.3V.
Refer to Table 3: for the electrical characteristics.