AT86RF401E ATMEL [ATMEL Corporation], AT86RF401E Datasheet - Page 34

• Manufacturer Part Number: AT86RF401E
• Description: Smart RF Wireless Data Microtransmitter
• Manufacturer: ATMEL [ATMEL Corporation]

34
AT86RF401
• Bit[5:3]: ULC[2:0]
The unlock count (ULC) bits count a certain number of reference clocks, after which the
unlock detect circuit looks for a number of cycle slips determined by CS[1:0] before
making the loc detect signal go low. The ULC bits essentially control the blackout period
of the unlock detect circuit. The unlock counter is reset by the KEY signal rising (if
ENKO is asserted), or by the LOC rising edge, or by the UPOK signal being set high.
Table 14. PLL Unlock Counter Definition
• Bits[2:0]: LC[2:0]
The Lock Count (LC) bits control a counter that, after a number of reference clocks,
cause lock detect to go high. This counter will reset if a cycle slip or a reset signal occurs
(which happens if TXE goes low), if an out-of-lock condition occurs, if the crystal oscilla-
tor frequency is too low, or if the VCO feedback frequency is too low.
Table 15. PLL Lock Counter Definition
ULC[2:0]
LC[2:0]
000
001
010
011
100
101
110
111
000
001
010
011
100
101
110
111
Number of REF Clocks of Delay
Clocks of Delay
Number of REF
1024
1024
128
256
512
128
256
512
16
32
64
16
32
64
8
8
1424F–RKE–12/03