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at OSCIN (or RXCLK) can be determined upon power-up.
Also, this clock has near 50% duty cycle, because it is derived
from the VCO. As a result, CLKOUT1 should be selected before
CLKOUT2 as the primary source for system clock distribution.
CLKOUT2 is a divided version of the reference frequency, f
and can be set to be a submultiple integer of f
where L = 0, 1, or 2). With L set to 0, the output of CLKOUT2 is
a delayed version of the signal appearing at OSCIN, exhibiting
the same duty cycle characteristics. With L set to 1 or 2, the
output of CLKOUT2 is a divided version of the OSCIN signal,
exhibiting a near 50% duty cycle, but without having a determi-
nistic phase relationship relative to CLKOUT1 (or RXCLK).
,
OSCIN
L
(f
/2
,
OSCIN
OSCIN
Rev. A | Page 38 of 48
Table 22. SPI Registers for CLK Synthesizer
Address (Hex)
Bit
0x04
(4)
(3:2)
(1:0)
0x06
(7:6)
(5)
(4)
(3:2)
(1)
(0)
Description
ADC CLK from PLL
PLL divide factor (P)
PLL multiplication factor (M )
CLKOUT2 divide number
CLKOUT2 invert
CLKOUT2 disable
CLKOUT1 divide number
CLKOUT1 invert
CLKOUT1 disable
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