DS3105 Datasheet, PDF (87/110 Pages) Maxim Integrated Products – Line Card Timing IC

Preliminary. Subject to Change Without Notice.
DS3105
Register Name:
Register Description:
Register Address:
PHLIM2
Phase Limit Register 2
74h
Name
Default
Bit 7
CLEN
1
Bit 6
MCPDEN
0
Bit 5
USEMCPD
0
Bit 4
--
0
Bit 3
0
Bit 2
Bit 1
COARSELIM[3:0]
1
0
Bit 0
1
Bit 7: Coarse Phase Limit Enable (CLEN). This configuration bit enables the coarse phase limit specified in the
COARSELIM[3:0] field. This field controls both T0 and T4. See section 7.7.6.
0 = Disabled
1 = Enabled
Bit 6: Multi-Cycle Phase Detector Enable (MCPDEN). This configuration bit enables the multi-cycle phase
detector and allows the DPLL to tolerate large-amplitude jitter and wander. The range of this phase detector is the
same as the coarse phase limit specified in the COARSELIM[3:0] field. This field controls both T0 and T4. See
section 7.7.5.
0 = Disabled
1 = Enabled
Bit 5: Use Multi-Cycle Phase Detector in the DPLL Algorithm (USEMCPD). This configuration bit enables the
DPLL algorithm to use the multi-cycle phase detector so that a large phase measurement drives faster DPLL pull-
in. When USEMCPD=0, phase measurement is limited to ±360°, giving slower pull-in at higher frequencies but with
less overshoot. When USEMCPD=1, phase measurement is set as specified in the COARSELIM[3:0] field, giving
faster pull-in. MCPDEN should be set to 1 when USEMCPD=1. This field controls both T0 and T4. See section
7.7.5.
0 = Disabled
1 = Enabled
Bits 3 to 0: Coarse Phase Limit (COARSELIM[3:0]). This field specifies the coarse phase limit and the tracking
range of the multi-cycle phase detector. The CLEN bit enables this feature. If jitter tolerance greater than 0.5 UI is
required and the input clock is a high frequency signal then the DPLL can be configured to track phase errors over
many UI using the multi-cycle phase detector. This field controls both T0 and T4. See section 7.7.5 and 7.7.6.
0000 = ±1 UI
0001 = ±3 UI
0010 = ±7 UI
0011 = ±15 UI
0100 = ±31 UI
0101 = ±63 UI
0110 = ±127 UI
0111 = ±255 UI
1000 = ±511 UI
1001 = ±1023 UI
1010 = ±2047 UI
1011 = ±4095 UI
1100 to 1111 = ±8191 UI
Confidential. Document Issued Under Non-Disclosure Agreement. Confidential. Document Issued Under Non-Disclosure Agreement.
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