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SNAU076B
LMK04800 Family
Revised - August 2014
Copyright © 2014, Texas Instruments Incorporated
www.ti.com
divider values which may cause a non-locked PLL, this warning by itself may no longer be assumed true.
It is up to the user to ensure the PLL dividers are programmed correctly.
To illustrate the proper programming of the LMK04800 device in dual loop 0-delay mode the following
case examples are provided. Note that in one of the cases, the feedback frequency from the clock output
matches the VCXO frequency and CodeLoader will display the proper frequency values.
Dual Loop 0-Delay (MODE=2 or 5) Case 1: For example the default configuration, 122.88 MHz CLKin,
122.88 MHz VCXO, of the LMK04808 has the following register programming.
Case 1:
Default Mode
No 0-Delay
Case2:
Default 0-Delay
Mode
(CLKout8 =
122.88 MHz)
Case 3:
Default 0-Delay
Mode (Updated
CLKout8 =
245.76 MHz)
Case 4:
Default 0-Delay
Mode (Updated
CLKout8 =
61.44 MHz)
Actual PLL1
VCXO Frequency
122.88
122.88
122.88
122.88
Reported PLL1
VCXO Frequency
122.88
122.88
61.44
245.76
PLL1 N
120
120
60
240
Actual PLL2
VCO Frequency
2949.12 MHz
2949.12 MHz
2949.12 MHz
2949.12 MHz
Reported PLL2
VCO Frequency
2949.12 MHz
2949.12 MHz
2949.12 MHz
2949.12 MHz
PLL2_N
12
12
12
12
PLL2_P (Pre-N)
2
2
2
2
PLL2 VCO Divider
Bypassed
Bypassed
Bypassed
Bypassed
CLKout8 Divide
12
24
12
48
Actual CLKout8
Output Frequency
245.76 MHz
122.88 MHz
245.76 MHz
61.44 MHz
Reported CLKotu8
Output Frequency
245.76 MHz
122.88 MHz
245.76 MHz
61.44 MHz
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