XRT8001 Datasheet, PDF (21/48 Pages) Exar Corporation – WAN Clock for T1 and E1 Systems

XRT8001
N x 1.544MHz
or
N x 2.048MHz
FIN
Where 1 < N < 16
CLK1
K x 56kHz
or
K x 64kHz
Where 1 < K < 32
XRT8001
WAN Clock
CLK2
K x 56kHz
or
K x 64kHz
Where 1 < K < 32
Figure 13. Illustration of the XRT8001 WAN Clock Device
Operating in the “Forward/Master” Mode
5.0 Configuring the XRT8001 WAN Clock into
the “Forward/Master” Mode
The user can configure the XRT8001 WAN Clock to
operate in the “Forward/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 4, and determine which combi-
nation of “Input Frequency” and “Output Frequencies”
(via PLL1 and PLL2) correlate with the desired configu-
ration.
Input Frequency
N x 1.544MHz
N x 1.544MHz
N x 1.544MHz
N x 2.048MHz
N x 2.048MHz
N x 2.048MHz
PLL1 Output
Frequency
K x 56kHz
K x 56kHz
K x 64kHz
K x 56kHz
K x 56kHz
K x 64kHz
PLL2 Output
Frequency
K x 56kHz
K x 64kHz
K x 64kHz
K x 56kHz
K x 64kHz
K x 64kHz
Value to Write to D4-D1
in CR0
0000
0001
0010
0100
0101
0110
Table 4. Listing of “Input Frequency and “Output Frequency”
Cases for “Forward/Master” Mode Operation
Rev. 1.01
21