XRT8001IP datasheet(23/48 Pages) EXAR

23 / 48 page

XRT8001

Rev. 1.01

6.0 The “Reverse/Master” Mode

When the XRT8001 WAN Clock has been configured to

operate in the “Reverse/Master” Mode, then it will

accept either a “56kHz” or a “64kHz” clock signal via

the “Reference Clock” input at FIN (pin 3). In response

to this clock signal, the XRT8001 WAN Clock will

output either a “1.544MHz” or a “2.048MHz” clock

signal, via the Clock Output pins (CLK1 and/or CLK2).

A simple illustration of the XRT8001 WAN Clock,

operating in the “Reverse/Master” Mode is presented

in Figure 14.

Figure 14. Illustration of the XRT8001 WAN Clock

Operating in the “Reverse/Master” Mode

6.1 Configuring the XRT8001 WAN Clock Device

into the “Reverse/Master” Mode

The user can configure the XRT8001 WAN Clock to

operate in the “Reverse/Master” Mode, by executing

the following steps:

Step 1 – Configure the XRT8001 to operate in the

“MASTER” Mode by pulling the “MSB” pin (pin 8) to

VDD.

Step 2 – Review Table 5, and determine which combi-

nation of “Input Frequency” and “Output Frequencies”

(via PLL1 and PLL2) correlate with the desired configu-

ration.

XRT8001

WAN Clock

XRT8001

WAN Clock

FIN

CLK1

CLK2

56kHz

64kHz

1.544MHz

2.048MHz

1.544MHz

2.048MHz

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