17.8.19 DPLL Control B

Name: DPLLCTRLB
Offset: 0x4C
Reset: 0x00000000
Property: Write-Protected

Bit 3130292827262524 
      DIV[10:8] 
Access R/WR/WR/W 
Reset 000 
Bit 2322212019181716 
 DIV[7:0] 
Access R/WR/WR/WR/WR/WR/WR/WR/W 
Reset 00000000 
Bit 15141312111098 
    LBYPASS LTIME[2:0] 
Access R/WR/WR/WR/W 
Reset 0000 
Bit 76543210 
   REFCLK[1:0]WUFLPENFILTER[1:0] 
Access R/WR/WR/WR/WR/WR/W 
Reset 000000 

Bits 26:16 – DIV[10:0] Clock Divider

These bits are used to set the XOSC clock source division factor. Refer to Principle of Operation.

Bit 12 – LBYPASS Lock Bypass

ValueDescription
0Normal Mode: the CLK_FDPLL96M is turned off when lock signal is low.
1Lock Bypass Mode: the CLK_FDPLL96M is always running, lock is irrelevant.

Bits 10:8 – LTIME[2:0] Lock Time

These bits select Lock Timeout.

LTIME[2:0]NameDescription
0x0DEFAULTNo time-out
0x1-0x3Reserved
0x48MSTime-out if no lock within 8 ms
0x59MSTime-out if no lock within 9 ms
0x610MSTime-out if no lock within 10 ms
0x711MSTime-out if no lock within 11 ms

Bits 5:4 – REFCLK[1:0] Reference Clock Selection

These bits select the CLK_FDPLL96M_REF source.

REFCLK[1:0]NameDescription
0x0XOSC32XOSC32 clock reference
0x1XOSCXOSC clock reference
0x2GCLK_DPLLGCLK_DPLL clock reference
0x3Reserved

Bit 3 – WUF Wake Up Fast

ValueDescription
0DPLL CK output is gated until complete startup time and lock time.
1DPLL CK output is gated until startup time only.

Bit 2 – LPEN Low-Power Enable

ValueDescription
0The time to digital converter is selected.
1The time to digital converter is not selected, this will improve power consumption but increase the output jitter.

Bits 1:0 – FILTER[1:0] Proportional Integral Filter Selection

These bits select the DPLL filter type.

FILTER[1:0]NameDescription
0x0DEFAULTDefault filter mode
0x1LBFILTLow bandwidth filter
0x2HBFILTHigh bandwidth filter
0x3HDFILTHigh damping filter