LMX25311778EVAL National Semiconductor, LMX25311778EVAL Datasheet - Page 31

• Manufacturer Part Number: LMX25311778EVAL
• Manufacturer: National Semiconductor

Specifications of LMX25311778EVAL

• Lead Free Status / Rohs Status: Not Compliant

2.9 REGISTER R8
2.9.1 XTLMAN2 -- MANUAL CRYSTAL MODE SECOND ADJUSTMENT
This bit also adjusts the calibration timing for lock time. In the case that manual mode for XTLSEL is selected and the OSCin
frequency is greater than 40 MHz, this bit should be enabled, otherwise it should be 0.
2.9.2 LOCKMODE -- FREQUENCY CALIBRATION MODE
This bit is controls the method for which the VCO frequency calibration is done. The two valid modes are linear mode and mixed
mode. Linear mode works by searching through the VCO frequency bands in a consecutive manner. Mixed mode works by initially
using a divide and conquer approach and then using a linear approach. For small frequency changes, linear mode is faster and
for large frequency changes, mixed mode is faster. Linear mode can always be used, but there are restrictions for when Mixed
Mode can be used.
2.10 REGISTER R9
All the bits in this register should be programmed as shown in the programming table.
2.11 REGISTER R12
Even though this register does not have user selectable bits, it still needs to be programmed. This register should be loaded as
shown the Complete Register Content Map (section 2.03) .
LOCKMODE
0
1
2
3
Description
Linear Mode
Mixed Mode
Reserved
Reserved
LMX2531LQ1146E/1226E/1312E/1415E/1515E
All but the following options
Conditions on Options
Works over all options and all valid OSCin Frequencies
31
Never use this mode
Never use this mode
Conditions on OSCin Frequency
f
OSCin
≥
8 MHz
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