fdbck

         VCO freq register counters

      
Module Instance Base Address Register Address
i_clk_mgr__clkmgr_csr__10d10000__perpllgrp__SEG_L4_SHR_ClockManager_0x0_0x1000 0x10D1007C 0x10D100A0

Size: 32

Offset: 0x24

Access: RW

Important: The value of a reserved bit must be maintained in software. When you modify registers containing reserved bit fields, you must use a read-modify-write operation to preserve state and prevent indeterminate system behavior.
Bit Fields
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16

Reserved_1

RO 0x0

fdiv

RW 0x0

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

fdiv

RW 0x0

fdbck Fields

Bit Name Description Access Reset
31:24 Reserved_1
Reserved bitfield added by Magillem
RO 0x0
23:0 fdiv
Fractional synthesizer center frequency control word. 
The HP PLL IP will initial operate at the frequency based on the Mdiv and Fdiv values set at Reset or PD state. 
It can be only set while the HP PLL IP is at Reset or PD state. It cannot be switched dynamically.

If ictl_pll_fastref_en_nt is 1'b0, Fref_eff <=200MHz
If ictl_pll_fastref_en_nt is 1'b1, Fref_eff <=312MHz

Fref_eff = (Fref/ictl_pll_arefdiv_nt_[3:0])

Freq_mul: It is a multiplier that consists of an integer portion and a fraction portion.
If ictl_pll_fefb_en_nt = 0 and ictl_pll_extfb_en_nt = 0
Freq_mul = (ictl_pll_mdiv_nt_[9:0]) + ((ictl_pll_fdiv_nt_[23:0])/(2^24))

If ictl_pll_fefb_en_nt = 1 and ictl_pll_extfb_en_nt = 0
Freq_mul = (ictl_pll_mdiv_nt_[9:0]) + ((ictl_pll_fdiv_nt_[23:0])/(2^24)) * ictl_pll_clkslice0_div_[10:0]

If ictl_pll_fefb_en_nt = 0 and ictl_pll_extfb_en_nt = 1
Freq_mul = (ictl_pll_mdiv_nt_[9:0]) + ((ictl_pll_fdiv_nt_[23:0])/(2^24)) * ictl_pll_clkslice<0/1/2/3>_div_[10:0]

HP PLL Voltage-Controlled Oscillator (VCO) Output clock frequency is equal to PLL reference clock effective frequency multiplied with frequency multiplier.
Fsynthvco = Freq_mul * Fref_effective

If ictl_pll_fastref_en_nt = 1'b0,
600MHz >= ((Fsynthvco)/(ictl_pll_moddiv_nt_[3:0])) >= 3* Fref_eff

If ictl_pll_fastref_en_nt = 1'b1,
600MHz >= ((Fsynthvco)/(ictl_pll_moddiv_nt_[3:0])) >= 1.5* Fref_eff

Fock_pll_clkslice<0,1,2,3> = (Fsynthvco)/(ictl_pll_clkslice<0,1,2,3>_div_[10:0])
RW 0x0